https://www.cyberciti.biz/faq/how-to-curl-ignore-ssl-certificate-warnings-command-option/
adding the -k option worked that out
curl -s -k -L -H "PRIVATE-TOKEN: _KkSwrw3nBoSe47uSzoP" -X GET --data "search=$1&search_namespaces=true" https://gitlab.selectiont.com/api/v4/projects/