A statement released by the church said: “The news of Rohan 'Fred' Shand's death in Kingsthorpe sent a wave of shock and grief over so many of Northampton's communities.

Source: https://www.northamptonchron.co.uk/news/people/details-released-for-fred-shands-funeral-as-hundreds-expected-to-pay-respects-to-northampton-teenager-4131354

The Mandalorian agreed due to Boba Fett and Fennec Shand's help in rescuing Grogu in season 2. After agreeing to the job, Djarin stated that he first wished to visit Grogu to present him with the formerly crafted Beskar chain mail.

Source: https://screenrant.com/mandalorian-season-3-recap-book-boba-fett-what-happened/