I purchased a roaming plan for USA but every time I try to make a call it says network busy.

[Bud52]

Tmobile

[softech]

HI @Kampfoster  (and @Bud52 )

Critical part to US roaming depends on T-Mobile/AT&T coverage and whether you can connect successfully onto either network.

If the phone is not connecting to T-Mobile/AT&T, change the Network Connection from Automatic to Manual and select and test both T-Mobile and AT&T and see which one you can connect.

With voice issue, make sure VoLTE is enabled on the device setting.  And if it does not work, try to change the Network to T-Mobile ONLY, and change  Preferred Network Type or Network Mode to 2G and see if the calls go through.
Also, you can download VoIP app TextNow as a workaround to make calls and text if you have Wifi or if your roaming has data component and data  is working

[hTideGnow]

HI @Bud52 

which network you connected to?

Try both AT&T and T-Mobile

[Bud52]

Florida 

[Kampfoster]

I think text works and I m using wifi. How do I connect to a phone network?

[hairbag1]

@Kampfoster 

You must connect to either AT&T or t-Mobile. Has the phone been volte enabled by PM ? Which state are you in ? Is data and text working ?