How do you get
You need to generate one and save the generated one somewhere.
Only during generation you will be able to access secret access and you need to store it somewhere safely. If you don't store it during generation, you need to create one freshly.
You can only have maximum two, so delete older one(hopefully nobody should use it now, or else they will be screwed :) ) and generate newer one and use AWS_SECRET_ACCESS_KEY from that.
How to access ?
Login using your credentials.
Only two can be active at a time.
If you do not have the secret access key, You can delete older one and generate newer one.
After generation, it will prompt you whether to save the file.
Note down the values.
This is the only instance you will be prompted to save file/note down the secret key.
If you miss this, you need to generate new one again :)