Best answer by drhouse
I am sorry about what happened to your phone. It is mentioned on this thread that it is not waterproof, but is water resistant. Check: https://uk.community.huawei.com/p30-series-30/water-inside-the-p30-pro-camera-5583#post31163
Your best course of action would be to contact Huawei service centre (08000 886 700) and arrange your phone to be collected for repairs. If your phone is not within their repair obligations, they will contact you with the total cost for the repair.
Hopefully you have your data from the phone with you all backed up, as Huawei does not retrieve data nor keep or transfer any of it to a new replacement device when provided.
Hope this helps!