The error message is indicating exactly what is wrong.
You are trying to convert a string "33300109396272646795" to an INT64 numeric value.
If you compare the value
33300109396272646795
to the maximum value for an INT64
9223372036854775807
you can see, that "33300109396272646795"
cannot be converted to INT64.
It is too big!
See
Int64.MaxValue Field (System) | Microsoft Learn[
^]
It might also be a good idea to read this documentation about C# numeric types:
Integral numeric types - C# reference | Microsoft Learn[
^]
A solution would be to use a different conversion method "Convert.ToUInt64" as described here:
Convert.ToUInt64 Method (System) | Microsoft Learn[
^]
UInt64 can hold values from 0 to 18,446,744,073,709,551,615