Based on the image, the process for making an epoxy resin keychain can be described as follows:

Prepare a variety of nail polish colors and mix them with UV epoxy resin according to personal preference, then pour into a mold shaped like small fish.

Cure with a UV lamp for 120 seconds. Make sure all the little fish are completely hardened before removing them from the mold.

Mix epoxy resin in a 3:1 ratio, prepare a mix of light green and transparent resin and pour into the mold.

Wait for 24 hours to allow the resin to fully harden.

Arrange the prepared fish, petals, or green stickers into a preferred style, and fix them in place using UV epoxy resin.

Pour another layer of 3:1 epoxy resin for sealing.

Wait another 24 hours for the sealing resin to harden, then demold to retrieve the finished product.

Note: If bubbles appear in your final product, you can use UV epoxy resin to fill them. During this process, you may need to gently coax the bubbles out using a needle or another tool, and then use the UV lamp again for localized curing if necessary.