About inserting the symbol lambda into the paper.md

Hi, sorry I don't know if this is the right place to post this question. I'm interested in inserting the lambda symbol as an inline equation. ``` a parameter lambda ( $\lambda $ ) ``` However, I got ``` Latexmk: ====List of undefined refs and citations: Missing character: There is no 𝜆 (U+1D706) in font [NewCMSans10-Book.otf]:mode=node;script=latn;language=dflt;+tlig;! [makePDF] Run #1 Rc files read: NONE Latexmk: Run number 1 of rule 'lualatex' This is LuaHBTeX, Version 1.15.0 (TeX Live 2022) restricted system commands enabled. Latexmk: Getting log file '/tmp/tex2pdf.-6dcaa6318cd2907b/input.log' Latexmk: Run number 2 of rule 'lualatex' This is LuaHBTeX, Version 1.15.0 (TeX Live 2022) restricted system commands enabled. Latexmk: Getting log file '/tmp/tex2pdf.-6dcaa6318cd2907b/input.log' Latexmk: Summary of warnings from last run of *latex: =====Latex reported missing or unavailable character(s). =====See log file for details. [WARNING] Missing character: There is no 𝜆 (U+1D706) (U+1D706) in font [NewCMSans10-Book.otf]:mod ``` The symbol lambda is a widely used symbol and I'm sure that there is a way of inserting this as an inline equation, I wonder if I could get some help with regard to how to insert this symbol, please? Thank you.