I installed and activated ACF plugin and when I tried to use it (name: Google Maps just same as the tutorial) on a post page, it showed the error message:
Oops! Something went wrong.
Please help fix this. Thank you so much in advance.
Please check this tutorial https://wpgmp.flippercode.com/docs/how-to-assign-location-using-acf-plugin/
You need to insert the code in your activated theme functions.php. In this tutorial you will find a respective code and related steps to display maps using acf.