If you are already selling direct & online, it is definitely a smart move to approach retailers. The wholesale channel is a great way to grow market share, points of distribution & volume for your products.
As mentioned by Peter & Chloe. The best way to proceed is to identify and approach the right retail partners for your products. Be direct, go to their store, learn about them, talk to their staff, and ask if you can speak to their buyer, then tell your story. Whether a yes or a no, you now have that contact and can build the relationship.
Pricing is also important. Research the typical margin expectations for similar products. Ensure you have calculated your margins so it is profitable for the retailer & for your business. Remember you are giving away margin in order to gain volume.
Then go for it. You’ll learn a lot just by putting yourself out there. Go well!