Ask your customers who use Homvio to share their home with you. They go to Settings → Access Sharing → Manage Access → Grant Access and enter your email — they can share the whole home or specific items. (To share one item, they can also use Grant Access in that item's ⋯ menu.)
There's nothing to accept — the next time you open your dashboard, a shared home appears on the Properties tab under Shared Properties, and items shared on their own appear under Shared Items. Make sure they use the email address on your Homvio account. Shares are view-only.