The My Bindle app supports uploading QR records that use the Smart Health Card (SHC) format.
Below are some links where you can access some of the most commonly requested or used SHC QR codes. If you don't see your provider in the list below, you can see if it is listed in this registry of providers who are using the SHC format.
If you do an Internet search for the website of the government entity, pharmacy or provider where you were vaccinated, you should hopefully be able to find a link where you can download a QR code that contains your specific vaccination information. For example, if you were vaccinated by St. John's Medical Center you could enter "St. John's Medical Center SHC QR code" in the search engine of your choice and it would hopefully direct you to a website where you can access your QR code.
It will likely ask you to verify your information including name, date of birth and possibly even social security number.