License Your Sophos UTM
If you selected PAYG, you don’t need to license Sophos UTM as the license has already been bundled with the AMI. You can also use a 30 day free trial for Sophos UTM(Auto Scaling) to test the deployment before purchase.
Note – Free trials will be automatically converted to paid subscriptions upon expiration.
When using BYOL versions of Sophos UTM, you’ll need a license file to unlock the UTM subscription features during free trial and production. You can store the BYOL license file in an S3 bucket, which is loaded during the boot up process. After the free trial, you can upload the production license in Management > Licensing > Installation section, and once the license had been uploaded details will be shown on the Management > Licensing > Overview tab.
For more information on BYOL, please contact aws.marketplace@sophos.com.

Sophos UTM Licensing Tab