I will suggest you use Storage Configuration feature of bolt cloud. You can refer this link https://www.boltiot.com/workshop-content-beta.php for simple documentation. Also, enable data download option in the script so that you will able to know the proximity sensor value. You can enable data download option by adding this line to your js file. dataDownload('true');
The sample code snippet for plotting line graph is
After completing all the steps, open console in chrome and see any error or warning message is there. Let me know in case you need further asstitance.