However, you could instead try form hosting type marketing form, just copy whole code in Form page record and add you site to whitelist rule, it’s easier than form capture and I’ve found no difference compared with the capture form.
I made a success embedded form in my wordpress site.
I recommend you try Insert Html Snippet plugin for your wp, you can insert HTML code directly into your page/post block when edit the content so it’s separate completely with PHP code.
Below is my wp page with embedded form:
Submission in Insights:
Hope it helps.