How to print custom characters on a thermal printer?

The company is currently working on a project. The thermal printer needs to be controlled to print receipts. Reading the official manual is really painful. I honestly have never seen such bad documentation. . .
Now that I’m done complaining, let’s get down to business. I have a few questions about thermal printers that I’m not sure about

1. Thermal printers have several working modes, and the usage scenarios of each working mode

2. How to print custom characters

I hope the great gods will give you some advice, thank you very much

The following is the official document’s description of printing custom characters

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The company is currently working on a project. The thermal printer needs to be controlled to print receipts. Reading the official manual is really painful. I honestly have never seen such bad documentation. . .
Now that I’m done complaining, let’s get down to business. I don’t understand a few issues about thermal printers

1. Thermal printers have several working modes, and the usage scenarios of each working mode

2. How to print custom characters

I hope the great gods will give you some advice, thank you very much

The following is the official document’s description of printing custom characters