Pass url parametar from O365 page to client web part

Hi,

What I am trying to achinve is to pass query string parametar from O365 page to client web part.

E.g https://...sharepoint.com/sites/Test/pages/TestPage.aspx?MyQueryStringParametar=123

I want to be able to read the MyQueryStringParametar in client app part.

How can I accomplish this?

Thanks

Brano