Hi.
If the LLP is stuck in a position wherein they only have 2 designated partners and 1 is died, than in such a case, you have to firstly appoint a new designated partner filing LLP Form-4 (Notice of appointment, cessation, change in name/ address/designation of a designated partner or partner. and consent to become a partner/designated partner) and LLP Form-3 (Information with regard to limited liability partnership agreement and changes, if any, made therein) along with a Supplementary deed.
After new DP appointment procedure is completed, than you may carry on the process of striking off the LLP.
Note :- before appointing any new designated partner, do check whether he/she has a DIN/DPIN. If not, than firstly you have to file LLP FORM DIR-3 (Application for allotment of Director Identification Number)
A draft LLP Supplementary agreement was shared by someone on this cs mysore group. I am attaching the file for your reference.
In mumbai, we use ₹500 stamp paper. Do check yours