1. Register on alchemy.com

2. Create App

Create an app choosing Polygon as a chain and Polygon Mainnet as Network.

3. Click View Key

4. Copy HTTP

5. Add New Network to Metamask

1. Go to Settings → Networks → Add a Network.
2. Add a new network with the following settings:
   • Network Name: Polygon Alchemy
   • New RPC URL: an HTTP link from Alchemy.com (see #4)
   • Chain ID: 137
   • Currency Symbol: MATIC
   • Block Explorer URL: https://polygonscan.com
3. Click Save and change Network in Metamask.