Please see here and the comments below there. See also this FAQ and section 6 there.
A user-created tutorial here. Another advice in this comment. (A plain text version here.)
Please note that VEGAS Support for the VEGAS product lines is not the same as MAGIX Support.
EDIT October 13, 2022
NOTE: Support pages UPDATED in mid-October 2022. Please see the comment below.
VEGAS Support pages updated in mid-October 2022
Please see https://www.vegascreativesoftware.info/us/support/
Click (e.g.) "VEGAS PRO" there and on the opening page scroll to the bottom to "Contact Support". Proceed to "Send e-mail" > Fill the Support form and "Submit support request".
Please see also here: https://www.vegascreativesoftware.info/us/forum/support-system-upgrade--137601/
It shows the method from the https://www.vegascreativesoftware.com/us/ web site.
In addition. Online Live Chat (mainly for pre-sales and registration help) is available from Monday to Friday 12 p.m.-4 p.m. U.S. Central/CDT (UTC/GMT-5) from March 10, 2024 to Nov. 3, 2024, after that CST (UTC/GMT-6) to March 9, 2025)
Go to www.vegascreativesoftware.com/support and use the chat widget in the lower-right-hand corner to chat directly with a support rep.
(Note: It's also possible that Live Chat is available at other times, e.g. some hours during European daytime, now as well.)