CPA = Cost per action, generally meaning this type of offers that if you sell them, you earn a comission for each sell. Also include leads, installs, and any kind of action that the user do through you.
Snapchat is like WhatsApp (or even worse, because it doesn't have groups or anything like that). Most people recommend redirecting your traffic from other sources (IG, TikTok, FB, ...) to your Snapchat, and then DM them in Snapchat.
But from my point of view, this loosens the funnel, A) they may not have SC, which in fact outside US is completely underused (apart from UK not sure)...
B) Why sending someone to an URL? The only good purpose of this, is that snapchat profiles are white hat, so it's unlikely any other SM platform will penalize you for sending people to SC (but they will if you send them straightly to your CPA).
So from my point of view, the sole purpose of doing this is like a soft-cloaking method.
Also found in another SC thread that someone showed me, that there are other methods that help you befriending random people.
If you search in the Play store for "snapchat friends" you will find a thousand apps...
https://play.google.com/store/search?q=snapchat%20friends&c=apps
The main problem is that there won't be any kind of segmentation. So I only see this valid for any kind of CPA that would be available in a generalist newspaper (like most Native ads)