this is currently actively investigated with a bounty. the old backend uses the Go SDK which currently isn’t officially supported anymore.
@VitalJeevanjot is working on a bounty to migrate the backend to nodejs and we will hopefully be able to share some good news here in the upcoming weeks, see [bounty] migrate Go backend to Node.js (CHF 800) · Issue #1 · aeternity/aepp-token-migration-backend-nodejs · GitHub
be assured that your funds are safe! you will be able to migrate the tokens if you still have access to your account holding your old ERC20 on Ethereum.
there is a way to do this “manually”. you should find somebody to help you with that or just wait until we provide another update here.
manual migration steps: