You can try to download glibc from the official source and install it:
wget -c https://ftp.gnu.org/gnu/glibc/glibc-2.29.tar.gz
tar -zxvf glibc-2.29.tar.gz
mkdir glibc-2.29/build
cd glibc-2.29/build
../configure --prefix=/opt/glibc
make
make install
Pay attention to avoid breaking your OS environment: you need to specify the prefix and configure the separate path when you are using it.
See this answer on how to use the alternate GLIBC.