Hi there, @anon71899553… assuming the structure of the URL is always the same, you can use Bubble’s :split by operator with the separator being a colon, and then add the :last item operator to the expression and you should get the desired result.
Aside: It would be nice if there were an API to the expression builder for adding stuff like this. (Because the “real” way to do this would be to turn the string into a URLSearchParamsobject and then just get the value of the place_id parameter. Basically, this already exists in the “get data from page URL” expression.)