Just to clarify, the evidence provided by opposition is not from exit polls. The evidence is genuine voting receipts from the machines that are supposed to be* guaranteed to each party’s site observers
*Opposition says many of their observers were removed without being allowed access to their polling site receipts to explain why they didn’t have them all
The electronic machines provide every voter a paper receipt that shows which candidate they chose. Voters are supposed to deposit their receipts at ballot boxes before exiting the polls.
After polls close, each machine prints a tally sheet showing the candidates’ names and the votes each received. Party representatives stationed at polling sites throughout election day get a copy of the tally sheet, and electoral authorities keep another one.