Routing input to output directly is not possible natively. You're going to need 3rd party software.
You will also get latency. You will also get the tinny sound of laptop speakers*. You will also quite likely have a headset socket which can only handle mono input [& designed for a cheap headset mic, not line-in].
I don't see it being a great idea, all in all.
Here's a QA with a list of the currently-available software for Mac that can do this. Mainly you get what you pay for - https://apple.stackexchange.com/questions/408600/capture-audio-correctly-while-capturing-video-calls-on-macbook-with-earbuds
The best of these apps [the Rogue Amoeba stuff] will cost more than a cheap set of speakers.
*I've never owned an Apple laptop but we have an M1 iMac here, with supposedly all-singing, all-dancing, Dolby Atmos, 6-channel yada yada… sounds about as good as a pair of $£€ 20 speakers from a supermarket/electrical retailer. I had to use one of those apps mentioned in the linked QA [SoundSource] to push an aggressive EQ curve into it to make it listenable.
(btw, I'm a sound engineer by trade. I'm picky;)