In Microsoft 365 Business Premium, it's easy to share files with people in your organization, but sometimes you will also need to share with people outside your organization. To share files securely with your customers, you can send a secure link.
For more tips like this, check out the working remotely playlist at www.youtube.com/FoetronAcademy . Also, if you need any further assistance then you can raise a support ticket and get it addressed.