Technically, “danger close” means that there are friendlies within 600 meters (or more for larger artillery) of the coordinates that you’re calling a strike on. You wouldn’t say “I need an airstrike, danger close” to have someone bomb your position, you’d say “I need an airstrike at coordinates X, danger close” to remind them to please do a good job and hit the target at X because if they miss, they’ll hit good guys.
But, I can’t think of any phrase that means “fire on my position” and the public has taken “danger close” to mean that. It would probably work for the OP.
As a bit of trivia… Apparently the last time a Broken Arrow was called was during the Battle of Ia Drang in 1965, but that’s not the last time a “we’re getting overran” call went out. 5th Special Forces and MACV-SOG had a different code word, “Prairie Fire*,” which meant the same thing as Broken Arrow. I don’t know how many times it was used, but it wasn’t exactly rare with those guys because they liked to take like 8 dudes out and observe the enemy from an arms length away. In 1971, a Prairie Fire emergency happened to two different teams in the same area on the same day.
*This can be confusing because MACV-SOG border hopping recon operations into Laos and Cambodia were also code named “Prairie Fire.”