Matching 'id' numbers and looping variable names into new column (Python)

I have two data frames pulled from an API:

1. df contains time series tag ids
2. t_name contains tag name: t_name['tag']

All I want to do is match 'ids' and map the tag name to a new column.

I was trying to get around using a for loop...but I couldn't even get that to work so I had to reach out to the big brains over here.

Thank you and let me know if there's anything else I can provide!