The Sales Channels indicate where each opportunity came from (e.g.: Google, WhatsApp, Website, Referral). Registering these channels helps with reports and organizing proposals and invoices.
Where it is located
Proposals and Invoices Settings → Sales Channels
You will see the list with: First name, Alias, Creation/Update Date and the action Delete. There is also the search and the button + New Sales Channel.
Create a channel (step by step)
Access Settings → Sales Channels and click on + New Sales Channel.
On the Edit Sales Channel, fill in Sales channel name