that’s a difficult proposition. I know in Hong Kong right now they are running a no try/buy policy meaning customers are not allowed to try on items pre purchase. MBIE should have some guidance on this on their website.
Many of the largest online retailers globally are clothing labels so there are plenty of customers who already buy without the benefit of trying the garment on for size/look. Depending on how your brand is positioned you could have a policy of no trying on before buying which customers will understand.
Is this an opportunity or even a necessity for your business to look at developing an online store as well? It will be some time before retail trading patterns start to get back to “normal” and you should expect that some of your customer base will be more open to online shopping than they have in the past. I would seriously be considering this as a new sales channel.