Second line with new Account ID ?

Hello together,

sorry for my bad english but I hope you understand my sentences.

I'm german and I bought for a trip to the USA an T-Mobile prepaid unlimited plan (eSIM).
Now I need an additional line for my other smartphone. In my T-Mobile account I have the possiblity to buy one more lines.
Can I buy one of these lines for my second smartphone or is the line only usable for the first registrated phone ? Or does I need an additional T-Mobile account for the second line?

And how will I get the eSIM information  for the second line (QR code via eMail ??)?

Maybe somebody of you can explain it for me.

Gracias

Mario