Lrdfrx I need to create various microsoft developer accounts and need unfortunately one phone number for each for sms verification (receiving code).
Bear in mind that MS tends to keep sending 2FA type of codes to that phone number every once in a while, if not every time you need to login to a new device. So consider getting numbers that work for at least for the time frame that you intend to keep the microsoft accounts for.
Free SMS numbers tend to have been abused (or will get abused very soon): so they'll get blacklisted. Along with the numbers, your account also will get blacklisted.