fix: add block term request

- use postAsJson function
- moderator and broadcasterIDs are query parameters

moderation.go

@@ -164,8 +164,8 @@ func (c *Client) GetBlockedTerms(params *BlockedTermsParams) (*BlockedTermsRespo
 }
 
 type AddBlockedTermParams struct {
-	BroadcasterID string `json:"broadcaster_id"`
-	ModeratorID   string `json:"moderator_id"`
+	BroadcasterID string `query:"broadcaster_id"`
+	ModeratorID   string `query:"moderator_id"`
 	Text          string `json:"text"`
 }
 
@@ -189,7 +189,7 @@ func (c *Client) AddBlockedTerm(params *AddBlockedTermParams) (*AddBlockedTermRe
 		return nil, errors.New("the term len must be between 2 and 500")
 	}
 
-	resp, err := c.post("/moderation/blocked_terms", &ManyAddBlockedTerms{}, params)
+	resp, err := c.postAsJSON("/moderation/blocked_terms", &ManyAddBlockedTerms{}, params)
 	if err != nil {
 		return nil, err
 	}