Use the nasal spray to soften the booger follow by using the nasal aspirator to suck it out. Or you could use a cotton bud to remove it too if you do not have a nasal aspirator, they sell cotton buds specially designed for babies!
some info:https://community.theasianparent.com/q/mummies-lo-3-weeks-plus-old-but-has-some-sticky-boogers-in-nose-i-wonder/1081171
sterimar nasal spray recommended by our PD
I use baby cotton bud to remove it out
Cotton bud