How to exclude part of a page from cache

Yes, you can achieve this using the ESI, here is more information: Edge Side Includes for WordPress ? LiteSpeed Blog (litespeedtech.com)

OK thank you!

I’ve had a look at the link but can’t see how to apply ESI to a gutenberg block. Is that possible?

ESI only supports for shortcode and widget , other elements may requires custom coding.

OK thank you.

Do you happen to know a good resource which explains how to the custom coding?

please check this page , basically , you will need to make the content you want , to be an individual function , then load into page by shortcode , widget, or functions

OK thank you.

I think I can go the widget route as the block I’m adding is to be displayed on every page.

I enabled ESI but I don’t see any additional widgets created, particularly the ‘resent posts’ widget mentioned here:
https://blog.litespeedtech.com/2017/09/06/wpw-esi-and-litespeed-cache/

Best Regards,

Steve

for widget you may need to use classic widget interface

Ah, OK. Thank you.