How to run external display from boot?

I was givin this laptop with the built in display broken(can only see bottem right corner) and ive tried connecting an external monitor to it but it won't switch to the display till windows is loaded. It has the Novo button(onekey recovery) and I've tried all standard keys for entering bios in hopes of blindly switching default display, also have tried using fun-ction keys to switch displays. I'm wondering if there is a key to enter bios that i haven't figured out(f1,f2,f10,del,esc,f12 haven't worked) the Novo button just brings me to the recovery screen(and not a menu where I can select bios or boot like other Lenovo models). If anyone else has had this issue or someone can direct me to a fix I'd be grateful.