How to install Google Tag (GA4 tag) on my Square website?

[Forginthecraft]

I keep getting emails from Google Analytics about taking action on my Google Analytics to be set up for GA4 but tbh I don't understand what or how I need to do this... 

Square is not listed as a supported platform, so it looks like I need to do it manually, but I haven't got the foggiest about website codes / headers etc... 

I have read Adam7's answer there: https://www.sellercommunity.com/t5/Weebly-SEO/How-do-I-install-my-Google-Analytics-UA-code-or-Google... and I don't understand it. 

Here's the relevant extract from it: 
Note: If you are going to use Google Analytics 4 and want to add your GA4 tag, copy the code from Google's Google Anlaytics 4 installion guide, then replace the MEASUREMENT_ID with your own. Once you have the modified code, add it to your site following the steps in the guide above. If you are using the Square Online editor, you will want to take the modified code and add a header code field instead of using the Google Analytics field. 

I don't know what my own MEASUREMENT_ID would be or where to find it. I use Square Online editor (I think - if it is what I'm thinking it is), but I really don't know where I need to add the header code field. 

Can anyone help with layman's terms, screenshots etc... please? 

Thank you!!

[Breffni]

Hi @Forginthecraft - thanks for your post. 

As a moderator, I have limited training or resources on Google Analytics, unfortunately. I can only share what's publicly available on our support centre. 

I did find a different thread from Adam here that does mention Google Analytics 4 measurement ID that may be helpful. 

Hopefully, another seller who has set this up will be able to jump in here with some insights.  

[Forginthecraft]

Thank you for that. I shall check all this information out. I did find another post similar to mine, but unfortunately, the answers given weren't any more helpful. I could mostly do with step by step instructions and screenshots. Thanks again