It's easy to add comments to a milestone in the operations section of the platform. To do so, first go to the operations part of the job (contract has to be signed for this section to be enabled) by clicking the highlighted icon in the top navigation bar.
Once in the operations section, ensure that you have selected the right milestone by clicking the appropriate milestone name. To add a comment click on Miestone Feed. Enter a comment and click on Comment. 
Afterwords, your comment will appear in the milestone feed.
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