how to run composer install to create vendor directory?

[b0chard]

I am updating a client's website (1932washhouse.com). After I pushed the recent commit to github, it automatically passed the file updates to heliohost using a webhook. I have a composer.json file sitting in the httpdocs/ but I don't know how to do composer install to update the dependencies and install the new one I added?

I navigated to the PHP Composer option in the dashboard but it shows me this error notification: 

Quote

Could not load packages: the /.trash/owa/modules/base/composer.json file of the 1932washhouse.com domain is invalid. To fix the issue, click "Edit composer.json" and correct the composer.json syntax.

I tried clicking the change folder but it didn't show the option inside httpdocs/,  I also tried manually typing the content of composer.json file from httpdocs/ into that composer.json but it won't do.

Edited 1 hour ago by b0chard