tsibble | Tidy Temporal Data Frames and Tools | Data Visualization library

I'm trying to run different forecast modeling methods on a monthly tsibble dataset. Its head() looks like:

I'm able to convert the following df to tsibble object and plot using gg_season():

Problem I want to create a tsibble but it's unclear how to set the key and how to set the index. Not a tibble.

I tried the following:

What's the correct way of testing equality in a symbol?

I've tried

This is my original df and fitted model

I have converted a normal DF into a tsibble object and used that for my time-series forecasting. While fitting the model I experience the date format error- "Error in decimal_date.default(x) : date(s) not in POSIXt or Date format". As you could see from the below code- the converted tsibble object clearly identifies column "Week.1" as week date type. Could you please help me clarify why I'm still getting the date format when I fit forecast models to the tsibble object?

In fable's ARIMA function, we have the option to see all models that are evaluated with the trace = TRUE option. (Example below.) This output just prints to the console.

Is there any place that this model evaluation history is getting saved or is there any way to save the printed console output?

I created a tibble (named df) with a number and a vector inside:

I have been reading this book and been trying to use some of the same code, which require you to store your data as a tsibble. However when I try to use a specific code in chapter 3 on my own data, I can't get it to work.

First I load my own data, then I store it in a tsibble and the try to convert it to a tsibble (I don't know if this is the optimal way), but it seems that at some point along the way, I don't clarify what the quarterly dates are correctly.