Cracked drywall at joint near door?
Nails tend to work better for fastening metal bead than screws, but most people are used to using screws. Just make sure to pull the screws up flush with the edge of the bead. You'll likely pull more of the bead loose trying to get it pulled tight, but just keep going until no more mud cracks loose. As stated above, chip out ALL loose mud. A setting type compound would be best for at least the first fill coat to reduce "shrinkage" and number of coats. But if this is the only repair you have, probably not worth buying a bag. Ready mix will work fine, just need additional coat(s).......
If you can read this, thank a teacher. If you can read this in English, thank a soldier. Support our troops.