Previously, a CRM (written in PHP JS SQL) was created where orders are received. The CRM has many functions. One of them is automatic creation of TTN via Nova Poshta API, etc. For a long time, shipments were sent simply from an individual. After changes in the law, it is now necessary to switch to FOP. To do this, a FOP will be created, a contract will be signed with Nova Poshta, etc. And here, a mandatory condition is the installation and use of the checkbox PRRO software. Your task is to connect this checkbox PRRO to my custom CRM. That is, add my checkbox.php file and, of course, link everything with SQL. This will be a new tab called "checkbox" in my CRM where you can configure the checkbox itself (all data on forms, keys, licenses, opening and closing cash register shifts, automatic creation of fiscalization checks when the client pays for the shipment on Nova Poshta, sending SMS checks to clients, etc.). For example, you can look at the checkbox menu on third-party ready-made CRMs (LP-CRM or salesdrive) - screenshots of this CRM are attached below or on YouTube, where it clearly shows what the checkbox settings tab looks like in LP-CRM, enter a query on YouTube:

Connecting the Checkbox module - here the video clearly shows what the settings panel looks like and what should be in the settings.

 That is, there should be a Checkbox tab where I can configure my cashier, shifts, checks, etc.  The main task when creating TTN via Nova Poshta API is to query whether there is a connection with this remote checkbox PRRO, create a check, etc.  The Checkbox service itself provides a test mode, data, keys, etc., for web developers to set everything up before opening FOP. So, you can immediately start working by taking a test Checkbox account.  Shipments are sent only via Nova Poshta, cash on delivery. Therefore, fiscalization occurs only when the shipment is paid for at Nova Poshta. I want to warn you immediately that the code is written somewhat chaotically and was developed intuitively, gradually over 9 years. There is no strict structure as such. Currently, what we have is what we have. In fact, everything works. TTN is created automatically via Nova Poshta API. Updating the shipment status (i.e., in transit, at the branch, collected, etc.) is done manually. That is, press a button in the CRM, wait 5 seconds, and the current data is pulled. Perhaps Cron will need to be used here to automatically update everything. We will discuss the details during correspondence.