Terrible Voice Signal Strength

I am on a Telus Mobility prepaid plan with an Android 15 phone.  Voice signal strength is between 0 and 1 bar.  I sometimes can't make a call, and frequently the call cuts in and out.  Signal strength is -113 dBm  27 asu.  Mobile voice network type is LTE.  I have tried to turn on WiFi calling, but get an error every time.  Is there some kind of signal booster available?  Any ideas?