About "https://api.box.com/2.0/web_links"

I run the below code, but Box-API returns the error "status 400 code bad request, URL must be well-formed".

The pound "#" character in the "url" parameter causes this error, but I don't understand why Box-API wants to block. Does anyone know how to solve it?

curl -i -X POST "https://api.box.com/2.0/web_links" \
-H "Authorization: Bearer <ACCESS_TOKEN>" \
-H "Content-Type: application/json" \
-d '{
"name": "some title",
"url": "https://xxxx.com?#path=folder",
"parent": {
"id": "0"
}
}'