bibliography problem in latex

Question

I want to make bibliography for my tex. I have written this with ri identifiers in my bib document. but it shows ri in my text. what should I do

\documentclass[11pt,times]{article}
\usepackage{geometry}
\usepackage{dcolumn}
\usepackage{booktabs}
\usepackage{pdflscape}
\usepackage{graphicx}
\usepackage{placeins}
\usepackage{dcolumn}
\usepackage{xcolor}
\usepackage{booktabs}
\linespread{1.5}
\usepackage{subcaption}
\usepackage{amsmath}
\usepackage[colorlinks=true,urlcolor=blue,citecolor=blue]{hyperref}
\usepackage{multirow}
\usepackage[symbol]{footmisc}
\usepackage[title]{appendix}
\usepackage{caption}
\usepackage[english]{babel}
\usepackage{calc}
\usepackage{makecell}
\usepackage{ mathrsfs }
\usepackage{sectsty}
\providecommand{\keywords}[1]
{
    \small

    \textit{Keywords:} #1
}
\providecommand{\JEL}[1]
{
    \small

    \textit{JEL classification:} #1
}
\newcolumntype{N}{>{\centering\arraybackslash}m{.6in}}
\newcolumntype{D}{>{\centering\arraybackslash}m{2in}}
\newcolumntype{G}{>{\bfseries\centering\arraybackslash}m{2in+6\tabcolsep}}
\newcolumntype{?}{!{\vrule width 1pt}}
\usepackage[backend=biber,style=bwl-FU]{biblatex}
\bibliography{sample}
\newtheorem{assum}{Assumption}
\newtheorem{defini}{Definition}
\newtheorem{theorem}{Proposition}
\newtheorem{lem}{Lemma}
\begin{document}
    In courts exist some matching mechanisms between poor defendants and attorneys. USA's courts utilize two kinds of mechanisms. First, the court selects an attorney for the defendant. In this case, participated attorneys in the market matches randomly to poor defendants. The second is the voucher mechanism, in which courts devote specific budgets to every indigent defendant, so he employs his attorney. According to \cite{r1}, this mechanism leads to positive assortative matching on cases difficulty and attorneys quality.
\printbibliography
\end{document}

In courts exist some matching mechanisms between poor defendants and attorneys. USA’s courts utilize two kinds of mechanisms. First, the court selects an attorney for the defendant. In this case, participated attorneys in the market matches randomly to poor defendants. The second is the voucher mechanism, in which courts devote specific budgets to every indigent defendant, so he employs his attorney. According to r1, this mechanism leads to positive assortative matching on cases difficulty and attorneys quality.