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Click on your username in the top right and click Data Access Password:
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Enter a suitable label and click on “Generate new data access password”
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The password is shown. Click Copy to copy it to the clipboard. After this, you can use CTRL-v to paste it.
Data access passwords expire in 90 days, you can view the expiration time in the list.
If a password has expired, simply create a new one and update the password in the WebDAV client.