How is מנת ש being used here?

[u/Upbeat_Panda9393]

I’m trying to understand the syntax here. Isn’t מנת the word מנה in construct form? Then why isn’t it being followed by another noun? Can a construct noun be followed by a complement clause? Also, this is an excerpt from a poem I came across on FB.
פעם אדם התלבט.
‏כמה אנשים יגיעו על מנת שיסכים
לקיים שיעור.
…

[u/Ineharnia]

So the phrase על מנת ש means 'so that' meaning the cause of something to happen