Download fossil source code from:
https://www.fossil-scm.org/home/uv/download.html
Unpack it with:
tar -zxvf fossil-src-2.25.tar.gz

Download openssl source code from:
https://openssl-library.org/source/
Unpack it with:
tar -zxvf openssl-3.4.0.tar.gz
Put the unpacked directory under 'compat' directory
in fossil source code directory as 'openssl' (compat/openssl)

cd compat/zlib && ./configure && make
cd ../openssl
./config --with-zlib-include=../zlib --with-zlib-lib=../zlib
make depend
make
cd ../..
./configure --with-zlib=tree --with-openssl=tree
make
strip fossil