Tips on adding manually created GPX files to Strava?

I’m looking into this option as a way of getting more accurate map traces for runs in very built up areas (with poor) gps signal reception.

I created a .gpx file and then tried to load it as an activity to Strava. However, the Strava website told me that it wouldn’t accept it without time data. Has anyone got a workaround for this?

And/or, is there way of uploading a .gpx file directly into Citystrides?

I have used this tool on occasion when my watch acted up. I used the planned route from plotaroute as a basis, and made myself really slow so not to cheat Strava stats.

A note though: I found that routes usually just have 2 points for planned straight lines, and real GPS files of course have many. For City Strides that looks like you just teleported between those nodes and haven’t run in between. So you also have to make sure your resulting file has datapoints every few metres.