https://developers.activecampaign.com/reference/get-contact
https://developers.activecampaign.com/reference/create-contact-tag
を、参考にしてCurlで接続してみた

curl -v -H “Accept: application/json” \
-H “Content-type: application/json” \
-H “API-Token: xxxxxxxxxxxxxxxxxxxxxxxxxxx287123dc”\
-X GET \
https://{youraccountname}.api-us1.com/api/3/accounts/1

curl –http1.1 -v -H “Accept: application/json” \
-H “Content-type: application/json” \
-H “API-Token: xxxxxxxxxxxxxxxxxxxxxxxxxxxx287123dc”\
-X POST \
-d ‘{“contactTag”:{“contact”: 1,”tag”: 2 } }’ \
https://{youraccountname}.api-us1.com/api/3/contactTags

Crulで、検証できると、とても解りやすい