I have been with Callcentric.com for over 10 years now. It is a VOIP phone service that can direct calls to anywhere you want them sent. I am on the basic plan and incoming calls cost me nothing - I only pay literally pennies for outgoing calls (and since I rarely use the phone, that's fine). I pay about $5 a month (which includes 911 EMS). They also have unlimited use plans, and regional and global plans.
When we were in the UK I had a US phone handset connected to the internet through a VOIP adapter. My daughter's friends (or anyone) could call and we'd get a USA ring pattern (one ring, not the two quick of the UK) and knew it was an American call coming in, not a UK call. We could also dial anywhere in the USA as if we were IN the USA. (Or anywhere in the world, basically, but as if inside the USA). It was running me, I think, about $3 a month to keep the phone number and basic service while we were there (no 911 EMS).
The voip adapter worked anywhere, so no matter where we moved in the world as long as there was internet I could use that service with the same setup. When we got back to the USA and I finally had a cellphone delivered to us in the quarantine hotel, I forwarded my Callcentric number to it until we had an apartment and were settled. Alternately, you can use the system entirely from a laptop, I believe - including making and receiving calls and texts, but I prefer a handset.
For a while when we were in the UK I had it forwarded to my UK Sky cell phone. (No distinctive ring, but we got the incoming calls that way.) When I was traveling back to the USA I used an old USA cell phone in-country with a temp sim card, and had the CC phone number forwarded to it to avoid Sky's roaming charges. You can set forwarding to one number, multiple numbers simultaneously, or via hunting.
This system accepts and can send texts. The downside is that right now they don't send or receive overseas texts - only within the USA and, I think now Canada. I could still use it to get text codes, etc., while in the UK by setting the system to forward them to me as emails. It cost me an additional $1 per month to be able to send/receive USA text messages. Since I don't use a "smart" phone still, I get my banking and other codes on my laptop via email. Works fine.
Also, a nice feature - you can get a free "conference call" number to give to friends - the Daughter used this several times to get all her old friends together at the same time for a virtual party. Was especially nice during the first part of the pandemic when we were overseas, to be able to have a group of people "in one place" again to talk with.
Their dashboard gives you quite a bit of control over call treatments (forwarding, redirecting, spam-filtering, etc.). The one downside, really, is that all tech-support is done via trouble-ticket and can take 24 hours to get a reply sometimes. Plus you have to be comfortable enough with tech to follow their walk-you-through-it initial setup instructions. But if I could do it, pretty much anyone should be able to. Billing is set up to either allow you to deposit funds periodically or via direct debit to a credit card.
I do recommend this service highly. As I say, we've used it for at least ten years and I can count on one hand (with fingers left to spare) the number of times I've had problems with the service itself.