As you should already be aware Dynamics On-Prem version 9.0 is getting close to end of support.
This means that after the 11 of July of 2023 we will no longer support version 9.0 and we will only support version 9.1.
More information here.
This is 3 months from now.
We suggest that you start preparing your upgrades to the latest service pack as soon as possible.
Please follow this documentation to plan and execute your upgrade.
If you need help with your upgrade, don’t hesitate to open a support case.