To store your .txt data using the Walrus protocol, you can follow the HTTP API methods. First, you need to specify your aggregator and publisher endpoints. For example, set your environment variables like this:

AGGREGATOR=https://aggregator.walrus-testnet.walrus.space
PUBLISHER=https://publisher.walrus-testnet.walrus.space

Then, you can use an HTTP PUT request to store the file. Here is an example using cURL:

curl -X PUT "$PUBLISHER/v1/blobs?epochs=5" --upload-file "path/to/your/file.txt"

This command stores your file for 5 epochs. You will receive a JSON response with details of the blob, including the blobId which you can use later to retrieve the file.

Once you have stored your data, you can retrieve it using the blobId. You need to use the Walrus HTTP API to read a blob by providing the blobId you received after store operation. The steps to perform a read operation are well-documented and involve reconstructing the blob from its slivers stored on the network.

For further help and detailed examples, check the official documentation at the Walrus usage page: docs.walrus.site.