Importing old dashboards via curl statement

We are upgrading our Grafana env from 7.3.7 to 8.4.6
I wanted to import the existing dashboards to the new environment. If I export the json file and import it in the GUI this will work. In the previous version we also made a script that generated the json file and import that to Grafana via curl statement. That worked also. I’m trying to imp7ort that json file via curl statement to the 8.4.6 environment but i get the following message
{“message”:“Not found”}

in the logging
logger=context t=2022-06-10T11:42:41.92+0200 lvl=info msg=“Request Completed” method=POST path=/api/dashboards/d status=404 remote_addr= time_ms=13 size=24 referer=

the dashboard is not updated in Grafana. This is the command i use
curl -X POST -H “Content-Type: application/json” -H "Authorization: Bearer " -d @/opt/…/conf/tmp/dashboard.json https:///api/dashboards/d

try increasing the verbosity of the Grafana server logs to debug and note any errors. For printing to console, set the console logs to debug as well.