No , u can pump in any amount the interest rate is daily ya, so depends on which day u pump in and which day will take out.

Lets say ur loan amount is 100k and interest is 3% , if the month got 30 days, ur that month interest will be 100,000 * 0.03 /365*30 = 246.57

If u pump in 5k at 5th day of the month , calculation will be
100,000*0.03/365*5 plus 95,000*0.03/365*25

…

Just that each time take out excess money will charge u 25 ringgit

This i not sure, i remember got lock in period 5 years , dont have so many money to test this out