Assalaamou'alaikoum Wa Rahmatullah.
We should give charity of an amount that make us content and happy about. We give an amount of what we afford and we should feel good about it and expecting reward from Allah The Almighty.
It could be one dirham or 100 dirhams, it all depends upon your capacity in shaa Allah.
The more you give, the more Allah forgives your sins and erases your ranks,
The more you give, Allah returns you in abundance.
So you may give as much as you afford according to your capacity inshaa Allah..
Allah knows best