How can I put more characters on the QR code?

[Thibis]

I am trying to put +- 100 characters on the QR code. But I am having problems, because it need to be converted on array. What type of variable can I use to storage +- 100 characters?

When I try to put a char, a erro appears: " int8_t qrcode_initText(QRCode *qrcode, uint8_t *modules, uint8_t version, uint8_t ecc, const char *data);"

`String str;
ptos ++;
ptos ++;
e = horas;
total = ptos10000 + e100 + minutos;
Serial.println(total);
Serial.print(" = ");
str = String(total);
str.toCharArray(a,160);
Serial.print(a);
Serial.print("\n");

Serial.print("\n");
// Start time
uint32_t dt = millis();

// Create the QR code
QRCode qrcode;
uint8_t qrcodeNumeric[qrcode_getBufferSize(3)];
qrcode_initText(&qrcode, qrcodeNumeric, 3, ECC_LOW, total); `

Thanks for all