The Contributor role is a limited role, designed to support a workspace. Contributors cannot access the workspace through the user interface, thus they cannot use its functionality or see the workspace contents.
Contributors can only push data and other files into the workspace using the workspace-to-workspace Airlock. It is also possible to upload files using an API but another user would have to generate the upload token for you.
Uploading files as a Contributor
On the Workspaces homepage, you will not see the workspaces listed in which you have a Contributor role. Thus, you cannot simply upload files to them.
However, if you are a Standard User or a Workspace Administrator in another workspace, you can use workspace-to-workspace Airlock. Simply visit the workspace that you want to export the data from, and create an Airlock request.
In the Select a destination step, choose the 'Copy the selected datasets and files to another workspace' option. A dropdown will appear with a list of workspaces that you are a member of. It will also include workspaces where you have a Contributor role. Simply select that target workspace and create a request.
An Administrator of the destination workspace will be able to approve the Airlock request and import the data into a workspace.
Alternatively, if you do not have Standard User or Workspace Administrator privileges in any of the workspaces, you can still upload files using an API. However, you will need to obtain an upload token from one of the workspace users. You might also find it convenient to use this option if you are uploading a large number of files.