我想在脚注中插入以下链接（它在下面有效，但在我的 Latex 编译的 PDF 中无效）： https://ec.europa.eu/eurostat/cache/metadata/EN/migr_eil_esqrs_de.htm 在序言中加载：\usepackage{url}
\footnote{~For example, sometimes data are unavailable on third-country nationals who effectively returned to a third country (by type of return and citizenship) and third-country nationals who returned to a third country (by the destination country and citizenship). For this point, \textit{see}, e.g., \url{https://ec.europa.eu/eurostat/cache/metadata/EN/migr_eil_esqrs_de.htm}}
当我单击它时，它会将我导航到一个页面，并显示错误“您无权访问此资源。”
有人可以请教如何包含有效的 URL 吗？
以下是 MWE：
\documentclass{article}
\usepackage[utf8]{inputenc}
% Required package
\usepackage{amsmath}
\usepackage{multirow}
\usepackage{float}
\usepackage{graphicx}
\usepackage{booktabs}
\usepackage{threeparttable}
\usepackage{apacite}
\usepackage{multirow}
\usepackage[normalem]{ulem}
\usepackage[table]{xcolor}
\usepackage{longtable}
\usepackage{pdflscape}
\usepackage{fancyhdr}
\usepackage{afterpage}
\usepackage{geometry}
\usepackage{url}
\usepackage{caption}
\usepackage{cleveref}
\renewcommand{\&}{and}
\providecommand{\keywords}[1]{\textbf{\textit{Keywords}} #1}
\usepackage{hyperref}
\title{Doc}
\date{December 2022}
\begin{document}
\maketitle
\bibliographystyle{apacite}
Little is known even today about emigration patterns, including knowledge of returnees' demographics (\textit{see} e.g., Borjas and Bratsberg, 1996; Constant and Massey, 2002). Return migration is difficult to measure, which is one of the main constraints. Research on recent returns or repeated migration from Germany is scarce. Return migration is a challenging research area and is sometimes not fully understood because of several data availability constraints impede analysis of the topic. For example, migrant outflow records might be undocumented (see e.g., \citeNP{Erlinghagen2016}). Despite the German register requiring the person to de-register when leaving the host country, this might not happen. Also, data on these outflows are sometimes missing.\footnote{~For example, the Enforcement of the Immigration Legislation metadata information ``EIL," which is collected by German Authorities in compliance with regulations on Community Statistics on Migration and International Protection, lacks information on outflows.}
Data unavailability poses itself as one of the major challenges for analyzing return migration topics.\footnote{~For example, sometimes data are unavailable on third-country nationals who effectively returned to a third country (by type of return and citizenship) and third-country nationals who returned to a third country (by the destination country and citizenship). For this point, \textit{see}, e.g., \href{https://ec.europa.eu/eurostat/cache/metadata/EN/migr_eil_esqrs_de.htm}} This data unavailability exists despite member states' obligations to report the data sources used to Eurostat and provide the data to ensure statistical information completeness. All these reasons necessitate that both destination and source countries collect better data and statistics on return migration (\textit{see} Wahba, 2015). To fill part of this research gap and improve the information on return migration behaviors and magnitude, we examine whether the return has eventually materialized, which will be checked against declared return intentions in the empirical part of this paper. Nevertheless, several data limitations exist in answering this question for recent migrants, which we subsequently address in the limitations section.
\end{document}
围兜：
@Inbook{Erlinghagen2016,
author="Erlinghagen, Marcel",
editor="Tachibanaki, Toshiaki",
title="Anticipation of Life Satisfaction Before Emigration: Evidence from German Panel Data",
bookTitle="Advances in Happiness Research: A Comparative Perspective",
year = {2016},
publisher="Springer Japan",
address="Tokyo",
pages="229--244",
isbn="978-4-431-55753-1",
doi="10.1007/978-4-431-55753-1_13",
url="https://doi.org/10.1007/978-4-431-55753-1_13 "
}