With Ctrl+Shift+V
Ctrl+Shift+V pastes text only in browsers (Chrome, Edge, Firefox) and in everything you use inside them: Gmail, Outlook on the web, Google Docs, WordPress, Notion and most online editors.
In desktop programs it depends on each one. Word supports it in Microsoft 365; for other versions, see the Word guide.
In any program with PowerToys
PowerToys is a free Microsoft utility. Its Advanced Paste feature lets you paste as plain text in any app with Win+Ctrl+Alt+V.
The Notepad trick
The classic method is to paste the text into Notepad, copy it again and paste it where you need it. Pegatexto does exactly the same, but without opening another app and with extra tools to remove line breaks or extra spaces.
If the shortcut doesn't work in your app, paste the text in the box above, click Copy plain text and paste it wherever you want: it will arrive without any formatting.