How do I write the traffic rules to route everything through an sstp vpn?

How do I write the traffic rules to route everything through an sstp vpn?
I know to install the sstp-client.
But I have no idea how to route anything through it myself.
I know I shouldn't mess with it without knowing what I'm doing,
which is why I'm asking here on the forum.
The general location of where to configure it isn't that helpful for me.
As getting to the location/config needed to do it is easy enough.
It's how to modify it to do what I want that I can't wrap my head around.
Even just an authentic/legitimate (partial) example of the config file modifications would be helpful.
I know where to setup the proxy and traffic rules in general.
It's actually writing the traffic rules that I can't figure out.
Which is why I am asking here on this forum.

Duplicate.
See:

this technically isn't a duplicate.
This is asking it for a vpn.
While the other was asking it for a proxy.
I'd have to rewrite the other one to say vpn instead of proxy if this one on vpn's is taken down as a duplicate.

I just hope I don't get ostracized from here again before getting help on doing this with a vpn.
It's a local SSTP vpn that's exclusively just on my phone.
It doesn't connect phone/hotspot to an external server.
it routes the SSTP vpn connection through my phone's regular cellular data.

Then mark the other as solved by your last comment.

sorry about that

I would suggest you choose a Wireguard provider and subscribe, then install the Wireguard client on your router.

Have a look at these links:

and

Since when could you run a WireGuard service/server on your android phone?
That's not sarcasm, I'm legitimately hoping against reason that you know a way.
My hope is "against reason" because I know that that's not what you're saying.

What I said was:

install the Wireguard client on your router.

Then any devices connected to your router's lan will be using the vpn.

the vpn server is on my phone.
On the highest speed unlimited plan with my cellular carrier they drastically slow down your hotspot data when you hit the hotspot limit.
Down to around 12 to 16 kilobytes per second on average.
Slower plans don't do that to your hotspot... but f*** the slower plans.
Because our current averages around 5 megabytes per second give or take, and can reach 10 to 15 megabytes per second.
And our previous one averaged 300 kilobytes per second, and reached at most 1 megabyte per second.
This is is a lot faster, and I was able to get a hotspot app that can bypass that limit.
Although I'd prefer a rooted phone.
And rooted 5g phones are way too expensive.
My current phone is 5g, and is unrootable.
We also have the hotspot addon on our lines.
and it's not my decision to make on what plan we have anyway.

What does any of this have to do with OpenWrt?
This is an OpenWrt forum and you are posting on "Installing and Using OpenWrt".

Please find an Android developer's forum and ask there rather than waste people's time here.

the vpn server is on my phone.
posted this question because I want to have the router connect to it for my devices instead of having each individual device connect to it on their own.

are there better options for the connection setup I want to do?
Yes, but I can't afford them.