The adjustment only level is the data conversion level that ensures only manual journals will be entered in the secondary ledger. This level means that no data is copied from the primary ledger to the secondary ledger automatically. Instead, the user can enter manual adjustments in the secondary ledger to reflect the differences between the two accounting standards. This level is suitable for scenarios where the accounting methods or charts of accounts are very close between the primary and secondary ledgers, and there is no need to maintain detailed journals or subledger transactions in the secondary ledger. References: Primary Ledgers, Secondary Ledgers, and Reporting Currencies, High Volume Data Migration Considerations for General Ledger, Reporting Currencies - Conversion Level Balance

To use the Create Budgets in a Spreadsheet option, you need to have a budget scenario value and a scenario dimension member for your budget. A budget scenario value is a user-defined value that identifies a budget, such as FYXX Budget. A scenario dimension member is a member of the scenario dimension in the General Ledger balances cube that corresponds to a budget scenario value, such as FYXX_Budget. You can create budget scenario values and scenario dimension members using the Manage Budget Scenario Values task or the Create Scenario Dimension Members program. If you do not create these values and members, your budget will not appear in the Budget Name list of values in the spreadsheet. Therefore, the two reasons for your issue are:
* A value for the budget scenario is not created: You need to create a budget scenario value for your budget using the Manage Budget Scenario Values task. This task enables you to define and maintain budget scenario values and their attributes, such as description, start date, end date, and status. You can also specify whether the budget scenario value is enabled for budgeting and reporting. You need to enable the budget scenario value for budgeting to use it in the spreadsheet.
* The Create Scenario Dimension Members program has not been run: You need to run the Create Scenario Dimension Members program to create scenario dimension members for your budget scenario values. This program automatically creates scenario dimension members for all budget scenario values that are enabled for budgeting and do not have existing scenario dimension members. You can run this program manually or schedule it to run periodically. You need to run this program after you create or update budget scenario values to ensure that they are reflected in the scenario dimension.
Create Budgets in a Spreadsheet
Manage Budget Scenario Values
Create Scenario Dimension Members