SPA on load dynamic event

I have a trouble with SPA and dynamic actions.

I have an SPA. Index.php page contains two SPA routes with content blocks PageA and PageB. When route A is chosen and PageA page is loaded, I want to change a variable in SessionStorage putting params.param value.

I tried to create Dynamic Event on Ready or Load for App on the PageA but no success.

Is there a way to create some Dynamic Action when Page is loaded in SPA scenario?

I don’t want to include Serverconnect action on PageA, I know that I can use Dynamic Action SC success.

Thanks!