Many thanks @Zhi Lv - MSFT
Also, after a lot of research on Oqtane framework which can load rcl dynamically, i found that the static css & js files(s) of rcl project copied to Oqtane.Server project static files inside a folder as follow :
..\wwwroot\Modules\MyRCLProjectName\Module.css
..\wwwroot\Modules\MyRCLProjectName\Module.js
This copy process occures automatically & immediately after i build my rcl solution. In the MyRCLProjectName.Package project, we have debug & release cmd file(s) which execute this code(s) after i build entire solution :
..
XCOPY "..\Server\wwwroot*" "....\oqtane.framework-dev\Oqtane.Server\wwwroot\" /Y /S /I
..
To use these staic files, In Oqtane.Server and in _Host.cshtml's code behind, It create "link ..." tag dynamically inside head tag.
That's it!
However, Thank you very much ..