I wanna know if I can use a glue gun for metal bed to fix it and which glue gum would be recommend thank
Unfortunately your post is so short of detail that an exact answer is very unlikely Exactly what and where has broken, pictures would help as well If it's a weight bearing section then I doubt a glue gun would be any good, these are more for light weight DIY and hobby crafts Depending on what the damage is, and supported by pictures, a remedy may be available - just can't see it being the glue gun though