Why CRA ask for business number when I apply for HST rental property rebate?

I bought a pre-construction condo four years ago and registered a company to do software business two years ago. Now that the condo has been handed over and is being rented out, I am applying for an HST rebate, but the CRA is asking for a business number, which is not normally required in the form GST524.

I don't know if this business number is the one of my company. This property is being rented out by me personally and has nothing to do with my company, so I don't understand what the problem is. If I provide my company's business number, will there be any potential issue in the future?
Thanks.

Thank you!