Access a block's HTML code

Hello,

I am trying to access the HTML code of a page to modify the code of a gallery block I added. How can I go about doing that? I can't find the "Code Block" all the articles talk about, besides, I am not trying to add code from scratch, but want to modify the existing HTML. I am very familiar with WordPress where you can switch between blocks and code through a simple tab. Is there anything similar on SquareSpace? I also tried accessing the developers' website for SquareSpace but it seems like it's for building websites from scratch, while I already have a template. Help please! PS: I have a Business Plan

No, you can't modify a blocks HTML. You could view your pages source and find the HTML for the block and then copy that into a code block and make whatever edits you want from there but that's not really ideal.

What do you want to change about the gallery block?

As an aside there's nothing stopping you from enabling developer mode, everything you've done so far will be saved; it's literally a flick of the switch. Just be sure that you really need  developer mode before you enable it.