Twilio connection for new trunk does not work

[Cyprien]

Hello,
In admin -> Voice and chat -> Add trunk

When I add a twilio trunk in my instance by confirming account sid and token, I get the following error
"
Exception has been thrown by the target of an invocation.
"
In network logs I can see the following request :
https://****.3cx.cloud/xapi/v1/Trunks/Pbx.GetProviderAvailablePhoneNumbers
returned
400 Bad Request

{error: {code: "400", message: "Exception has been thrown by the target of an invocation."}}

The credentials are correct, the twilio account has phone numbers. I followed this guide https://www.3cx.com/docs/sip-trunk/twilio/
The 3CX account is almost empty, brand new.

Is this a bug or am I doing something wrong?

 

[KyriacosS_3CX]

Did you follow auto-setup or manual? Auto expects certain parts of the setup on the Twilio side not to have been done already - while manual assumes that you have already made some preparation on the Twilio side.

 

[Cyprien]

I selected auto-setup, the manual option is not available.
What parts should not have been done ?

 

[Cyprien]

I tried deleting the elastic trunk I created in Twilio. But I am still getting the error

 

[YiannisH_3CX]

In which stage of the process do you receive this error? Do you pass the authentication stage? Also do you have a trial of a paid account?

 

[Cyprien]

I don't pass the authentication stage.
When I confirm my Twilio credentials it fails with the error I sent.
I have a free SMB account https://www.3cx.com/smb/
The twilio account is a paid one.