I was following this video at the end it shows how to do basic stuff with Radare2 (r2).

When I try to set a break point with:

db 0x004005bd

Where 0x004005bd is the first address of the main function that just does:

push rbp

But after I run the db command it tells me:

Cannot place a breakpoint on 0x004005bd unmapped memory. See dbg.bpinmaps

I understand what it says, but how do I fix it ?