Good day. I am trying to setup telnyx into VAPI, https://docs.vapi.ai/advanced/sip/telnyx on step number 4 "Set this value to match your Vapi SIP URI" Where to get my Vapi SIP URI?

To get your Vapi SIP URI, choose a username and format it as sip:your_username@sip.vapi.ai, then use this in Telnyx’s “Translated Number” field to route calls correctly..

Is my user name equals my email address? because I can't find field "User name"

No, your SIP username in Vapi isn’t your email, it’s a unique name you choose to create a SIP URI, which you then use in Telnyx’s “Translated Number” field..