No, Infinito did not use one of the standard ways to create a Byron wallet.
And they went out of business a while ago (https://www.infinitowallet.io/). So, no support anymore … and no sending from Infinito itself.
I could not find out how they derive from the seed phrase.
In https://forum.cardano.org/t/how-to-restore-my-ada-byron-wallet-by-private-key/114665, two users reported that they were somehow successful, maybe with the private key and not the seed phrase. But unfortunately they did not give any details (and the latest of them was deleted and suspended for scam although I do not see a reason for that).