Marionette requires a storage to keep KYC documents, logo etc.
You have to choose Choose and configure one of :following storage.
Amazone S3:
Amazon S3 - object storage built to retrieve any amount of data from anywhere.
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If these keys are missing, they can be created on the page “My Security Credentials” → “Access keys” (access key ID and secret access key)
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Google Cloud Storage:
Google Cloud Storage - is a managed service for storing unstructured data. Store any amount of data and retrieve it as often as you like.
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Digital Ocean Storage:
Digital Ocean Storage - your data, stored securely – without surprises. Spaces makes it simple to store your data at any scale, with a beautiful interface, powerful API, and zero pricing surprises.
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See Storage configuration details here.