Do I need to complete On-the-Job-Training (OJT)?

Not always. Under point 66.A.45(c), OJT is required for the endorsement of the first aircraft type rating within a given AML category or subcategory, except category C.

For a subsequent aircraft type rating within the same category or subcategory, OJT is normally not required.

OJT must comply with Appendix III, Section 6 to Part-66. The list of OJT tasks and the programme must be accepted before the OJT starts by the competent authority that issued the AML. Reference: point 66.A.45(c), GM1 66.A.45 and Appendix III, Section 6 to Annex III (Part-66).