Library to send large amount of data over 433 MHz
Radio modules send packets of data (and for very good reasons) so, if the total size of the data you want to send is greater than the packet limit, you have to engineer a higher level system (called a protocol) that can split your bigger message up into chunks that can be handled by the .h file.

I'm not saying one isn't available and indeed you may find one but, if you don't find one, you are facing the design of a protocol to handle bigger messages. It's not too difficult - imagine splitting the data you wish to send into 64 byte chunks and appending a single byte at the start of the data that describes the packet payload: -


As being a full message
As being a start of message (message overruns 64 bytes)
As being a mid message
As being an end of message (i.e. the last few bytes of data in the message)


This is enough information for your receiver code to reconstruct the original message but make sure you do good error checking if there isn't sufficient in the .h code. And also make sure your receiver "acknowledges" each packet received as being error free.

You might also wish to embed an address that makes your transmission and reception more robust or even add a packet count to the mid message marker byte. You have a maximum of 77 bytes for the payload so you have a few bytes spare for improving integrity but, the minimum payload system is 1 byte header and 76 bytes of payload (which may include other checks like CRC).