Max_P , 13 hours ago

I’ve had my phone for at least 4 years but it runs well,

What’s the exact phone model? I’d be really surprised such a phone wouldn’t support LTE, 5G was about to come out 4 years ago. Even the OG pixel should support LTE. Unless your issue is lack of VoLTE support, which sometimes can be remediated with root or custom roms. Although I find the Internet portion to be more useful anyway, as you can just route the calls over regular VoIP and use Signal or Matrix or Discord or whatever.

Unless it’s a Samsung, then you’re kind of SoL into the fix by modding department, you’re stuck with what regular Android apps can do.