The naive answer would be to automate it: put up a Stripe or Paypal form and let them pay for your product.

However, if you're in B2B, the client would need to trust you, as in meeting you, the sales process, even training. What I would do is not automating the sales process, but the leads process: so you don't waste time in leads that are just passing by or checking out your product. With those you could arrange a meeting and then perhaps close the sale.

After you get some clients, you could hire someone to do the sales process you can't do. Or, if you have some savings, you can hire right away and ignore the previous paragraph.

Another option would be to have a sales co-founder, but that's another story.