I have read through and tried question 1 and question 2, however I still can't get to work. The autocomplete does not complete, TexStudio can't find the citation. I am using subfile if that matters.
When I include only \addbibresource in the main file, instead of my custom style, doesn't work, if however I include the biblatex package too it works fine.
Compiling results (pdflatex, biber, pdflatex) are fine.
\documentclass[11pt,a4paper]{memoir}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{graphicx}
\usepackage[stretch=10]{microtype}
%***********************Document*******************
\usepackage{mystyle}
\begin{document}
\cite{Johnson2014}
\chapter{something}
\end{document}
And the style:
% Declare that this style file requires at least LaTeX version 2e.
\NeedsTeXFormat{LaTeX2e}[1994/06/01]
% Provide the name of your page, the date it was last updated, and a comment about what it's used for. typography, graphics, maths, sectioning
\ProvidesPackage{mystyle}[2022/07/19 custom LaTeX style]
% Now paste your code from the preamble here
%
\setfloatadjustment{figure}{\centering}
\setfloatadjustment{table}{\centering}
\g@addto@macro@floatboxreset\centering %esse tbm centraliza
\usepackage[backend=biber,style=abnt-numeric,language=english,alldates=long,sorting=none,hyperref,bibencoding=utf8,citecounter=true,]{biblatex}
%
\makeatletter
@ifpackageloaded{biblatex}{\addbibresource{new_refs.bib}}{\bibliography{literatur}}
\makeatother
%\DeclareFieldFormat*{citetitle}{#1}
\appto{\bibsetup}{\sloppy} %
%
% Finally, we'll use \endinput to indicate that LaTeX can stop reading this file. LaTeX will ignore anything after this line.
\endinput

#include:biblatexnow, but TexStudio still showsCitation Missingeven after Relaunch+ Idefix refresh structure. – G. Bay Sep 14 '22 at 21:37