bash: /usr/bin/curl: Argument list too long

Problem

exec curl alert “bash: /usr/bin/curl: Argument list too long”

image=base64 test.jpg
curl -X POST -F 'image=${image}' "url"
# alert message
bash: /usr/bin/curl: Argument list too long

how to fixed?

image=base64 test.jpg -w 0 > ./base64_image
curl -X POST -F 'image=@base64_image' "url"