How to recover wallet by importing private key on testnet?

I want to test the functionality of wallet recovery via private key import on the testnet. Preferably thru an online service.

I only want to test the functionality so that I can verify that it's basically working since I'm working on some Python code that I want to use on the mainnet later.

So for that, I don't want to download the whole blockchain but instead, want to verify that my private key is generated correctly and I can access the funds that way. But I can't find any possibility to do that on testnet...

EDIT: I did not use mainnet for anything yet. I'm exclusively used testnet to create the wallet and get some coins and want to verify on testnet the wallet recovery thru private key

Testnet uses a different address format than mainnet, you can not view or verifying anything about the mainnet on testnet, they are separate.

You can test your method from the origin by using testnet funds instead.

Alternatively, you can test on mainnet with a small amount of funds to confirm your recovery method is working the same as it did on testnet (which it should).