You can share a flight plan at http://simflightplan.com/staging/download/ by clicking the Share Button at the top (next to the Save Button). You have options to type an addtional summary, include the list of waypoints and distances, and post under your own simflightplan username if you want.
You can also include a featured image if you took a screen shot in flight. The image must be a .jpg or .png file and cannot be larger than 2MB. The native image width is 1024px for the best appearance, and cropping or shrinking your image to that size will generally ensure that it will be less than 2MB.
Hint: You can use Windows Snipping Tool or Snip And Sketch to take a screenshot in flight and use Paint to adjust the size of the image. Although there are many other free tools available, including from many of the graphics cards manufacturers.
Check out the video above to learn how, as well as the other videos in our How To playlist on YouTube at https://youtube.com/@Simflightplan