The {{COMPANY}} token pulls its value from the Company Name field on the external job board. Please refer to the Token glossary for more information.
To check the company name for an external job board, go to the Job Boards & Posts page. (Configure icon 
> Job Boards & Posts)
Click the ellipsis icon 
next to your external job board, then click Edit Board Settings.
Find the Company Name field.
The value input into this field will populate when the {{COMPANY}} token is used.