Hello :)
I created 5 content types. They are listed in a column.
When a new item is created:
IF the value of the column “how can we help you” is equal to “ I want to book a meeting”
THEN change the value of the column “ content type” to "meeting request"
I cannot locate the proper action in the list. Mr Google is not helping me.
You can use "Update item" action under SharePoint and there you should set value of "Content type Id" column as shown in below screen shots
Hope it will helpful to you and if so then Please mark my response as Best Response & Like to help others in this community