If the previous English Test provided in the previous visa applications has a grade of B1 level and above and is still in the list of accepted English test provider, then you don't need to retake the test (even if the test certificate is already expired). ILR requires the applicant to have a grade of at least B1. Previous visa applications have lower level grade requirements, A1 for entry to UK and A2 for extensions.
This is one reason why I always advise to take the B1 level test from the start of immigration journey, to minimise retakes for future visa applications.