Click text link "Download or watch" then again Download - and you will be able to download without download manager

or use emule ( or likes ), I shared the file as

ed2k://|file|EECH_1.15.0.zip|782343769|5231626113DE677ECE902045E2AE2B8E|h=IMYWXWIWHSJJ2GR3N4Z3AEPDN424EAOW|/

and the next file also contains readme ( first post here ) and also includes eech-smoke-1.14.0.exe

ed2k://|file|eech_1.1.5.0_all_files.zip|783187724|FC1FA575C21A484BA7B5C07E02BBBA68|h=HQAXEXHJ3W6H4SQ5F7IY4GBV4RQREAQS|/