Solution box and cleaning solution

I purchased Dreame D20 ultra robot cleaner this week. I can see that there is a slot to place the solution box however I guess it doesn't come with the product. Please let me know how can I purchase that and also from where can I purchase the cleaning solution?

Hi, D20 ultra does not support the cleaning solution tank. that slot is used to keep extra accessories like dust bag.

I have bought the Dreame L50s Pro Ultra. It cleans regular stains like the spills easily but NOT able to clean the some small sticking things to floor tile. What to do

I recently purchased L50 plus and started using from 2 days, my observation is we were told that this are exteded ones but does not have that feature  it is not cleaning along the border leaving nearly 75mm from from wall and we have to clean again.
Also there is no mention of warranty or guarantee. I have taken extended warranty and in that also there is no mention of what all are covered and from which date to date. - Customer expects transperency for winning trust. Hope I shall recieve stratight response from team.