Let us know how Stripe works out. Normally they require a SSN on the account and/or a person in the states + a physical bank account (no EMI).
You have to submit form 5472 to the IRS. There are many resources available online about how to do it.
https://www.irs.gov/forms-pubs/about-form-5472
If you're not comfortable doing it yourself, hire an accountant to do it. The company that you formed the LLC with might be able to help you find a suitable accountant.Thanks! If I've just formed it (still waiting for the EIN), when will I have to send these forms (I found that I also have to fill up Form 1120)? Do you think I can do it myself or I should get an accountant?