I validated too quickly your answer.
I’m scripting under Shell (Bash).
I found the good solution:
NAME_ITEM="my beautiful item"
USER="user"
PASSWORD="strong_password"
URL="https://my.beautifulsite.com"
URIS=$(bw get template item.login.uri | jq ".match="0" | .uri=\"${URL}\"" | jq -c)
bw get template item | \
jq ".name=\"${NAME_ITEM}\" | \
.login=$(bw get template item.login | jq ".username=\"${USER}\" | .password=\"${PASSWORD}\" | .uris=[${URIS}] | .totp=null")" | \
jq '.organizationId="123abc"' | \
jq '.collectionIds="456def"' | \
jq '.folderId="789ghi"' | \
jq '.notes=null' | \
bw encode | \
bw create item && bw sync