Capital gains offset against capital loss

Dear community

I would appreciate it if someone could shed their insights on off-setting capital wins against capital losses when submitting taxes in Germany.

Are there any associated restrictions? E.g. Can you offset losses by selling a stock against the capital gains received by a Tagesgeld interest?

Can usual tax apps (E.g. Wundertax, Steurgo) can handle capital losses/gains? I used them in the past but I do not remember an option to attach supporting documents. (E.g. statements from the banks or brokers).

Thank you so much for your input.