Shopify shipping label without tracking and use USPS tracking number labels

[grch-tyfbmh]

 

i’m not sure if this can be answered here, but i can’t seem to find much online and i’m not sure where else to ask except perhaps usps. 

you can get tracking label stickers for free from the usps website. i ordered some. 

i noticed there is an option (the cheapest option from what i can tell) when creating a shipping label through shopify, to ship for cheaper without a tracking number. 

what i’m wondering is could i choose this cheaper option of shipping without a tracking number and just add my own- by using a tracking number sticker i got from the usps site? i’d like to know thoughts, if you think or don’t think it’s possible, if you’d tried it and it was successful or not.

i hope that makes sense!

i’ve uploaded an example picture of what i’m talking about for the shipping options in case!

thank you in advanced!