Solved The phone number is not displayed in the letter

You may try using this setting in the contact form module:

Message Pattern
Here you can define the custom pattern for the email Message. Fields should be included in following format – %%field_id%%. For example if you want to include the field with id = phone and field with id = message, then you can use the following pattern: My message is %%message%% and phone number is %%phone%%. Leave blank for default.

Taken from: https://www.elegantthemes.com/documentation/divi/contact/