Explanation
Three steps that are required when deploying changes via change sets are:
Create the change set in the sandbox org. This is the first step where the administrator selects the metadata components that they want to deploy and adds them to a change set in the source org, which is usually a sandbox org.
Upload the change set to the target org. This is the second step where the administrator sends the change set from the source org to the destination org, which is usually a production org or another sandbox org.
The administrator needs to have a deployment connection with the target org and permission to upload change sets.
Deploy the change set in the target org. This is the final step where the administrator validates and deploys the change set in the destination org. The administrator needs to have permission to deploy change sets and resolve any deployment errors or warnings.
Verified References:
https://help.salesforce.com/s/articleView?id=sf.changesets_create_outbound.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.changesets_deploy.htm&type=5

Explanation
Three steps that the administrator should do to implement this functionality are:
Create an email template. An email template is a reusable message that contains merge fields that are populated with data from records when the email is sent. The administrator can create an email template for the Payment Summary object that includes information such as the payment amount, date, status, etc.
Create an email alert action. An email alert action is a type of action that sends an email to one or more recipients when a flow executes. The administrator can create an email alert action that uses the email template created in the previous step and sends it to the owner of the associated account when a new Payment Summary is created.
Create an approval process on the Payment Summary object. An approval process is a way to automate the approval of records based on certain criteria and actions. The administrator can create an approval process on the Payment Summary object that requires an approval after review from a designated approver.
Verified References: https://help.salesforce.com/s/articleView?id=sf.email_templates_create.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.flow_ref_elements_action_email.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.approvals_creating_approval_processes.htm&type=5

Explanation
The best way for a user to view the information exchanged between the payment platform and the external payment gateways is to navigate to Payment Gateway Logs related list on the corresponding Order Payment Summary. A Payment Gateway Log is a record that captures the request and response messages between the payment platform and the external payment gateways, such as Stripe, PayPal, etc. A Payment Gateway Log has a lookup relationship to the Order Payment Summary object, which represents a payment made for an order or part of an order. A user can use the Payment Gateway Logs related list on the Order Payment Summary page to view the details of the payment transactions, such as the request and response payloads, status codes, timestamps, etc. Verified References:
https://help.salesforce.com/s/articleView?id=sf.order_management_payment_gateway_log.htm&type=5https://h

Explanation
The best way for the administrator to meet this requirement is to modify the compact layout on the Credit Memo object. A Credit Memo is a record that represents a refund or credit issued to a customer for an order or part of an order. A Credit Memo has various fields and related lists that display information such as the credit amount, status, reason, etc. A compact layout is a type of layout that determines which fields appear in the highlights panel at the top of a record page in Lightning Experience or Salesforce mobile app. The administrator can use the Object Manager to modify the compact layout on the Credit Memo object and add the Total Amount field to the compact layout. This way, the sales team can see the Total Amount field in the highlights panel at the top of the Credit Memo record page. Verified References:
https://help.salesforce.com/s/articleView?id=sf.order_management_credit_memo.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.compact_layouts_overview.htm&type=5

Explanation
Three steps that the administrator should take to implement this functionality are:
Create an External Data Source pointing to the external system's database. An External Data Source is a type of metadata that defines the connection and authentication information for an external system that stores data outside of Salesforce. The administrator can create an External Data Source using the Lightning Connect OData 2.0 or 4.0 adapters, which support read-only access to data in relational databases.
Create an External Object for each table of accounting data in the external system. An External Object is a type of custom object that maps to a table in an external system. The administrator can create an External Object for each table of accounting data that they want to access from Salesforce, and define its fields and relationships accordingly.
Create an Indirect Lookup field to connect to the Account. An Indirect Lookup field is a type of custom field that links a child External Object record to a parent standard or custom object record. The administrator can create an Indirect Lookup field on the External Object that references the Account object, and specify the external column name and value that match the Account ID.
Verified References: https://help.salesforce.com/s/articleView?id=sf.external_object_overview.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.external_object_relationships.htm&type=5