i need to update my mac to mac os version 10.15 is this possible on my model A1398?

Yes. See here: link-> How to get old versions of macOS - Apple Support

There's more than 20 different MacBook Pro models that use same identifier as you stated.

Lookup Mac Specs @ EveryMac.com

This could better help identify your Mac given specific model, order, EMC, model ID #s.

• How to get old versions of macOS - Apple Support

https://support.apple.com/en-us/HT211683

See details on models that could be upgraded from lower versions, to newer ones.