Node-Red page load question

I'm going to work after all the Node-Red pages are loaded.
ex) similar to onload, Changing html tag values, etc.

Is there a function called after all node-red pages have been loaded?

Not clear what you are trying to do. Which pages do you think need to load? Are you referring to a Dashboard or to the Node-RED Editor?

If you need a flow to only start once something else has, you either build the dependencies into the flow. Or, for lets say startup processing when you need some variables to initialise first, put the variable initialisation on the first tab so that it runs first. Then add a slight delay before your dependent flows start (using the inject node or a delay node).

Adding script src to page template is in use.
What you're trying to do now is try to change the values when the dashboard loads.
Not loaded through nodes. Is there any way not to use node?