My KWC Domo faucet leaks when pull out is in spray mode is this an easy fix

Probably needs at least one new rubber seal, you'd probably contact your supplier.

Various spare parts are shown in this manual (attached):

Hi Roger:
Spray mode creates more pressure in the internals, which will make any poor fit or bad seal leak.
The first thing I would do would be to check all coupling points to make sure they are tight.
I'd dry it completely, and then turn it on in spray mode for just a second, then use tissue to dab at the leak location to determine the exact point where it is leaking.
Once you've isolated the leak, fixing it is usually very straightforward.
Cheers