If you need to maintain regular access to the number (i.e. not a burner), MySudo, Hushed, and Twilio are all good. MySudo wins for out-of-the-box functionality, Hushed wins for privacy (they accept crypto), and Twilio wins for technical flexibility and customization.

Like someone else said, TextNow.com is great, but it requires a Gmail account.

Have you tried telnyx or twilio? managed myself to get telnyx number for verification purpose only, and it's working well