To create a B2 bucket and upload a file to it, you will first need to make sure that you have B2 Cloud Storage enabled on your account through the "My Settings" page in your account. When activating B2 on your account, you will be prompted to enter a phone number that must be verified via SMS. Being able to receive SMS messages is required in order to use B2.
Once B2 is enabled on your account, navigate to the page labelled "Buckets"
On the "Buckets" page you will see the option to "Create a Bucket"
When you select "Create a Bucket" you will be prompted to name it. The name you choose must be globally unique, meaning it cannot be a name already in use by any other Backblaze user. Once you have named your bucket, click the button labelled "Create a Bucket".
The bucket you just made will now appear on your "Buckets" page. You will also see a button next to the bucket you just created labelled "Upload/Download" . Click this to upload a file via the web interface.
You will now see the contents of the bucket, and another button labelled "Upload", click this button to Upload files.
You will then be prompted to either click the dialogue box to select files, or drag and drop files directly into the dialogue box to upload them.
Either drag the files you want or select the file you want after clicking the dialogue box and then click "open"
After selecting the file it will upload and show listed under the bucket you have created.
The maximum file size of a single file you can upload through the B2 Web Interface is 500 MB. If you need to upload larger files, you’ll have to use an alternate upload method.