Like many things, it is easy once you know how. The instructions on the internet usually missed one tiny critical piece of information. |←
Export a dashboard
In Grafana, select a dashboard. At the bottom of the display select |← (circled in the image). (This was the missing bit of information.)

- This gives you icons
- Download
- Content outline
- ->|
- Select Download. This gives

You can either Download the file, or copy to the clip board. Because Grafana is running in a browser, the downloaded file is in your normal Downloads directory. One download had a name dashboard-1791876486315.json
Importing a dashboard
In Grafana, select Dashboards

Select the +^ on the top line, and select import dashboard.
You can drag and drop a file to the area, or select from a file list.