It Always depends of the subject. Si on your case, the subject of the sentence is “I” (and you are a woman), you need to use “féminin”.

Exemple boy
I am a user.
Je suis un utilisateur.

Exemple girl
I am a user.
Je suis une utilisatrice.

It really depends of what is refering to..

It’s widely accepted to use feminine forms nowadays, especially when writing/speaking about an identified subject. Keep the masculine form for mixed plural groups as it applies.

Des policiers travaillent dans ce commissariat.
Cette policière m’a donné une amende.

Some title might be considered neutral, and therefore use a masculine form but it’s slowly changing and not evenly. Even military ranks are changing – I saw an article where a female colonel insisted on being called “Colonelle” in writing and an answer by another saying that she didn’t need it.

I still call my female doctor (and she calls herself) :

Docteur Trucmuch

So don’t worry about it.

Whatever form you choose, the most important thing is to stick to it. You might make some people cringe, but it’s better that they cringe because of ideology, than because your text is less readable because of form swapping.

A small particularity : if you are writing something that happen in the past (like a fiction) it might be better to stick to the masculine form most of the time. If you are describing something that happen in the past, just keep coherent.

Don’t use inclusive writing, unless you want to appeal to some people specifically. It makes the speaking/reading different that the writing and create confusion – especially if you address people with reading deficiency. Prefer to write a complete description than this shortcut.

Les tuteurs et les tutrices

is clearer than

les tuteur.trice.s