How to use Nextstrain seasonal flu graph as reference tree for Nextclade?

To Whom It May Concern,

Hi, my name is Isaac, and I am currently pursuing my undergraduate studies in bioinformatics in Malaysia. I am writing to you today because I have been assigned the exciting task of utilizing Nextstrain’s seasonal flu phylogenetic tree ( auspice ) as a reference to analyze and predict vaccine coverage using my own sequences. I am curious to know if it is feasible for me to incorporate my personal sequences into the existing tree and align them using Nextclade. Your guidance and support in this matter would be greatly appreciated. Thank you for taking the time to consider my inquiry, and I look forward to your response.