Hello @carlos-blanco-garcia, welcome to the Quick Sight Community!
All of the assets in Quick Sight can be converted into the JSON format by utilizing either the [describe-asset] or [describe-asset-definition] CLI or SDK commands. That will allow you to create a resource that can be migrated from the DEV to the QA account.
Analyses in Quick Sight also have a really helpful format, where you can create a template that can be shared with another AWS account so that the analysis can be moved easily. Here is the CLI documentation for creating an analysis template:
Then, for things like the datasource and dataset, you can check the other links that I attached.
Once all of those items are migrated to the new account, you can publish a dashboard utilizing the analysis you created from the analysis template. I would highly recommend testing all of these in CLI or running it locally with something like boto3 before putting it into Terraform to test out the process. Let me know if you have any further questions!