sevensthemes

i think u dont get it.

simple question

if i upload my theme to WordPress for free, how can i update my theme to new version ?

Just Upload the latest version & replace the old version with latest version ?
and how can user know that theme has a new version ?

What i mean is whoever buy my theme on marketplace such as creativemarket.com and if any update that i made their receive notification and their can update theme by clicking link on theme section.

when user click update, system will download the latest version of theme from my web. so their dont need to download update from marketplace and install and update. their can automatic update to latest version.

i dont know what people call this function. WP HOOK ? not sure.

what i mean by wordpress server is example.
example if theme twenty-twenty one has release a new update a user will get notification that tell the user the theme has a new version and user can update directly by clicking the link . that just example what i want to do.

Yes im using caching server level. i tried using wp-reset plugin to clean my cache and For your information im using multi site but with same theme. .i will show you. on this site i tried so many times clean cache, until i off the server cache plugin.
here the problem site . https://demo.sevensthemes.com/main-demo/
and here not https://demo.sevensthemes.com/marketing/

u noticed at icon box when we hover the box.