The default keyboard short key is Windows Key+Shift+S, You can change the shortkey if you like as well. But those videos give a little more info on it too. Where you host your pictures is not as important except that if you are trying to embed a picture for devs to see some sites are blacklisted on their network and there is no way for them to see them. I believe imgur is one of them. I use discord to host images, the important part is that you never delete the post in discord that you uploaded it to. To use discord to host, maybe make a private server, or send a message to a friend, whatever. Then click the image in discord and push "open original". It will open it into a browser, then you highlight it's address, and voila, your image is hosted and ready to be posted or embedded anywhere you want with no water marks, etc. And obviously since DPG has and uses an official discord, their firewall allows that traffic through. So you have no worries about whether or not they will be able to view the image you are posting.
Call me old fashioned but i still just prntscr and paste it into MSPaint and resize it to where I want it before throwing it on imgur.
