Calling Accounts

nicmair

Is there a reason I cant add a calling account, specificly a SIP one.  In the calling accounts section of the phone app, there is no option to add calling accounts?  I even tiorted side loading differenmt version of Google Phone, but they all seem to point to common setting area, with no option to add a calling account.  Be keen to know if this is just me (and/or a carrier restriction, which I doubt, as it worked fine on my Oneplus with the same carrier), or its a common across all owners, in which case why would UMI do this.