Is possible Freetrade can add start up stocks,i have researched some but are not on the app
What exactly do you mean by “Start-up”? One example is sufficient. FT routinely adds newly IPO’ed shares to its list of available stocks.
If per chance you mean pre-IPO stock: then that would not be possible on an official public exchange as such stock is private. To be clear you would need to directly invest in such companies either through crowd funding or via a pre IPO investment round or by approaching the owners directly and telling them you want to invest in them.
Check out Primary Bid or Crowdfunding