So that you can scan order lines to pick bins / totes you need to label you pick bins with unique identifiers. You can generate these identifiers as barcodes using any barcode generator. These should be code 128 barcodes, so that they can include numbers, letters and other characters.
Below are some websites that you can use to generate these barcodes:
Suggestions for Bin IDs:
In the above the letter represents the area that bins are put to after picking and the number represents its unique ID.
Example bin label: