What error are you getting exactly? According to the documentation for this endpoint here: Binance API Documentation the way I interpret the parameters is as follows:
yeah, I also tried this, it shows signature error, {“code”:-1022,“msg”:“Signature for this request is not valid.”}
But I could query other endpoints normally, like this one, /sapi/v1/lending/auto-invest/source-asset/list
I got the request like this, https://api.binance.com/sapi/v1/lending/auto-invest/plan/add?UID=*****&sourceType=MAIN_SITE&planType=SINGLE&subscriptionAmount=100.0&subscriptionCycle=WEEKLY&subscriptionStartTime=1&sourceAsset=USDT&flexibleAllowedToUse=True&details%5B0%5D.targetAsset=BTC&details%5B0%5D.percentage=60&details%5B1%5D.targetAsset=ETH&details%5B1%5D.percentage=40×tamp=1687484768479&signature=7aa173e93cd05cd5fd554a92c69f53c41c3ec7e0d16ed******