If you have an Android phone (even if just an old one you don't use anymore, or a cheap one you're willing to buy) and you're willing to root it and wipe all data on it, you can:
1. Unlock the bootloader (if not already done) (this will wipe your device)
2. Install Authy on it and log into your Authy account
4. Once rooted, you can access the Authy app data and extract the TOTP secrets, then import them into a different app (there's a script to make this easier here https://gist.github.com/gboudreau/94bb0c11a6209c82418d01a59d..., but you can also just go exploring manually in the root file system and find the Authy storage file)
It was somewhat of a pain in the ass to do this, but Authy really annoyed me with how difficult they make it to migrate off of their bullshit, so it was worth it to me to finally be able to delete their app after extracting the secrets this way.
1. Unlock the bootloader (if not already done) (this will wipe your device)
2. Install Authy on it and log into your Authy account
3. Root your device (I used Magisk https://github.com/topjohnwu/Magisk)
4. Once rooted, you can access the Authy app data and extract the TOTP secrets, then import them into a different app (there's a script to make this easier here https://gist.github.com/gboudreau/94bb0c11a6209c82418d01a59d..., but you can also just go exploring manually in the root file system and find the Authy storage file)
It was somewhat of a pain in the ass to do this, but Authy really annoyed me with how difficult they make it to migrate off of their bullshit, so it was worth it to me to finally be able to delete their app after extracting the secrets this way.