I’m new to regexp and mysql but I’m trying to match the following:

SELECT 'abc: bcd' REGEXP '(abc):?s?b'

This seems to work in a couple of online browser regex simulators but not in mysql.
I couldn’t find any similar questions but I may be missing the right keywords to find my answer
Any help would be greatly appreiciated!

SELECT 'abc: bcd' REGEXP '(abc):?s?'

This seems to work without the last ‘b’ but I want to specifiy a word following this part to look for

Tested using https://regexr.com/
and https://www.regextester.com/112633
using /…/ig