To Apply For
To Enlist, To Answer An Ad
する verb
If 応募 is "application" then the verb version is to apply for or to enlist.
The reading is the same as 応募's reading, though knowing the readings of the kanji will take care of things too.
あいつ、ビキニ姿のギャルが見れるからっていう理由だけで、市民プールの監視員の仕事に応募したんだよ。
He applied for a job as a lifeguard at the community pool only to see girls in bikinis.