You can send notification messages using the Notifications composer in the Firebase console. Though this does not provide the same flexibility or scalability as sending messages with the Admin SDK or the HTTP and XMPP protocols, it can be very useful for testing or for highly targeted marketing and user engagement. The Firebase console provides analytics-based A/B testing to help refine and improve marketing messages.
After you have developed logic in your app to receive messages, you can allow non-technical users to send messages per the instructions on the Notifications page in the Firebase Help Center.

you can get a 57% discount by agreeing to commit to a 3-year contract. Any usage over the commitment will just be billed at the standard rate. Since they only need 300 CPUs 30% of the time, will pick answer C so that we are not paying usage off 300 CPUs all of the time. This gives us a discount of 57% for 200 CPU's, huge cost savings.

The key reason I included this question is to clarify some terminologies that will be important for your estimates. The data size mentioned is a TB terabyte. Note the "byte". The speed is mentioned in Mbps, which is Megabits per second. Note the "bits". 8 bits make a byte. So, to get the actual number of bits transferred, you need to multiply the TB number by 8.
Total data transferred (in bits) = 100 * 1,000,000,000,000 * 8 bits
Speed = 100Mbps = 100 * 1,000,000. i.e. 100 million bits are transferred per second.
Hence time taken to transfer all the data = Total Data/Speed = 8,000,000 seconds.
Number of seconds in a day = 24*60*60 = 86,400
Total time taken in days = 8,000,000/86,400 = 92.59 days
Reference link- https://cloud.google.com/architecture/migration-to-google-cloud-transferring-your-large-datasets#online_versus_offline_transfer

Operations Suite is well integrated into Google and it s the recommended option.
References: https://cloud.google.com/products/operations