Lux Metals Corp. — Investor Presentation 2026

Feb 6, 2026

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I, Jonathan Marleau, M.Sc., P.Geo, do hereby certify that:

• 1) I am employed as a Geologist of Dahrouge Geological Consulting Ltd., located at 114 Rue St-Pierre, Montréal, Québec, H2Y 2L7.
• 2) This certificate applies to the report entitled "NI 43-101 Technical Report on the La Grande Project" (the "Technical Report"), prepared on behalf of Lux Metals Corp. and with an effective date of January 12, 2026 and signature date of January 12, 2026.
• 3) I graduated with a Bachelor's degree in Earth and Atmospheric Sciences from Université du Québec à Montréal (Montréal, Québec) in 2017 and a Master's degree in Earth Sciences from Université du Québec à Montréal (Montréal, Québec) in 2021.
• 4) I am a registered Professional Geologist (P.Geo) with the Ordre des Géologues du Québec (OGQ#2277).
• 5) I have worked in mineral exploration for a total of 8 years since graduating from university, during which time I have been involved in projects for precious and base metal and lithium in Canada.
• 6) I have read the definition of a Qualified Person ("QP") as set out in National Instrument 43- 101 ("NI 43-101") and certify that by reason of my education, affiliation with a professional association (as defined by NI 43-101) and past relevant work experience, I fulfill the requirements to be a QP for the purposes of NI 43-101.
• 7) I have been on the La Grande Project from May 20 to 30, 2024, and again on September 7 and 8, 2024.
• 8) I am responsible for the preparation of, and take responsibility for, all sections of this Technical Report that were prepared by me or under my direct supervision.
• 9) I am not independent of the issuer of this report.
• 10) I have worked on the Property since 2023, as a geological consultant for Electric Elements Mining Corp. and La Pulga Mining Corp.
• 11) I have read NI 43-101, and all items of the Technical Report have been prepared in compliance with this Instrument.
• 12) As of the effective date of this report, January 12, 2026, to the best of my knowledge, information and belief, this technical report contains all scientific and technical information that is required to be disclosed to make the Technical Report not misleading.

January 12, 2026

(Signed and sealed) Jonathan Marleau

Jonathan Marleau, M.Sc., P.Geo