I need to use accents to write in Portuguese and I can not. My computer uses Windows 10. How can I get accents?
Your question has nothing to do with LibreOffice. Refer to your operating system manual on setting up input languages.
You may find questions like Shortcuts for french accents on qwerty keyboards? give you a general idea. The key is to understand that the Alt-Gt key gives a number of options for typing European characters. You probably need to set the Keyboard as Portuguese, this is an operating system setting, not LibreOffice
A couple of specific LibreOffice thoughts.
In LibreOffice, as with Keyboards language is also country specific. So when you say English, it matters whether you mean English-GB or English-USA for example. These two QWERTY – International keyboards are NOT the same, especially the letter Ç (U+00c7).
As well as direct input using Alt-Gr keys, you can use two LibreOffice options if you do not need to enter two many letters. Using the example above.
1 Insert > Special Characters > select the letter needed.
2 Directly entering the Unicode letter with Alt-X. So c7 Alt x will give Ç whatever keyboard you are using.
Hope this helps Peter.