List of best mirrors for IP address 18.191.27.78, located in an unknown country.
I am very sorry, but no mirror was found. Feel free to download directly:
http://mirrordirector-mb.raspbian.org/raspbian/pool/main/q/qtx11extras-opensource-src/libqt5x11extras5-dev_5.15.15-2_armhf.deb