applying workflow to page

This may be useful for you - Link

Well, you need to create a workflow or update existing workflow object and add scope which will cover given page. Why would you want to do it in a code? What is the use case?

Thank you @Sunil Sharma Hi @Juraj Ondrus That's require from my client. I am writing code sync from the old node/page to the new node/page and need to sync all properties https://prnt.sc/1bdxqp2 How to sync all properties. Please advice! Thank you

that does not make much sense - why are you "synchronizing"? What does it mean? Is it within the same Kentico version and you want to move to another server? If yes, you can use backup and restore or export/import. If you want to migrate the data between Kentico versions, then you could use the import toolkit.
Or, why don't you create the same workflow (again, you can use export/import) on the target and then just "sync" the page? Just take the page (node) object together with the version history and sync it to the target.
But this sounds to me like a bit overhead - I would recommend considering using the consulting services and check this with our solution architect. I believe there is much better way how to achieve your need although I do not know all the details but I would say that you might spend more time on doing it like this rather than getting the best practice on a 30minutes session...