Hi Muhammad,
Sorry to say that iFixit doesn't have a guide for your repair, but there's Spanish site called Nadie Me Llama Gallina that does. Here's the screen replacement guide.
[link|https://www.nadiemellamagallina.com/en/manuales/smartphones-1/honor-715/honor-20-pro-1131/pantalla-completa-9992|Manuales / Honor 20 Pro / Fullscreen|new_window=true]
Replacement screens are readily available at all the major retailers such as eBay, Amazon and AliExpress; you'll need to find one that works for your location. Here's one of the first examples that came up on a cursory search.
[link|https://www.aliexpress.us/item/3256804875984816.html|New For Huawei Honor 20 LCD YAL L21 YAL AL00 Nova 5T Disply Touch Screen For Honor 20 Pro LCD YAL AL10 YAL L41 Replacement Parts|new_window=true]
Besides the replacement screen, be sure to buy precut adhesive sheets for the screen and the rear cover if they don't come with the display. To be honest, I usually buy a couple because they're easy to mess up and if you do then you have to wait until you can reorder to finish the phone.
Good luck; let us know how it goes.