osu! QuickPaste Image to BBCode
You can install the script on its Greasy Fork page here.
The script is free and easy to use. All you need is:
1. A imgBB API key. If you don't have it:
- Log in to https://imgbb.com/
- After that, go to https://api.imgbb.com/ and get your API key
Make sure to add your imgBB API key in the script where it says 'YOUR_API_KEY_HERE' (keep the quotes).
If you have any questions, feel free to ask in this thread. If you follow all the steps, it should work without any problems.

Note: If instead of using Ctrl+V you click on paste manually with the right mouse button, the script will also work.