therealsujitk datlechin You have to use composer require datlechin/lang-vietnamese As given in README.md.
Littlegolden datlechin You need to creat a new release in your repository first. You can't composer require one extension if it has 0 release.
aleveltech Littlegolden datlechin You may use datlechin/lang-vietnamese:dev-master if you don't want to make an release yet.
therealsujitk datlechin If you are only testing your extension, you don't have to upload it to packagist at all. You can simply copy the files to workbench.
therealsujitk datlechin Just type in Tag version for example v1.0.0 and Release title for example v1.0.0 and click Publish release.
