List of best mirrors for IP address 18.117.254.202, located in an unknown country.
I am very sorry, but no mirror was found. Feel free to download directly:
http://mirrordirector-mb.raspbian.org/multiarch/pool/main/q/qtbase-opensource-src/libqt5concurrent5-dbgsym_5.15.8+dfsg-7+rpi1_arm64.deb