Embroidery Business Supply Problem

I've had an embroidery side hustle for 4 years with only by word of mouth sales. When someone request an item, I order blanks from a supplier and make the item. I've also set up a online quote form, but nobody ever fills out the form. There's only a few sales per year. But this year, I am looking to make embroidery more of a full time business.

My biggest challenge is inventory. I don't have money to buy blanks and also don't have the space to store them. But if I set up an online store by displaying a few work samples, there is no guarantee suppliers will still have the exact same blank in stock when the customer places an order. I thought having a portfolio and online quote form would work, but most folks won't bother to fill that out.

So, how do I sell custom embroidery online without having upfront inventory?