Tree addition- Is it compulsory

Kindly inform me if tree addition is a must.
I profiled my 16S data using SILVA database with the DADA2 pipeline and I generated a tree through Phangorn package (phangorntree.rds), how do I upload this tree, I have been trying and it keeps on mentioning my data format is not alright.
How do I convert the .rds tree to nwk? tree file?
Can I analyze the data without the tree upload?
Thanks for your response.


The tree uploading is optional. You can analysis without it.

If you are familiar with R as you mentioned, you can use package such as ape( write.tree function) to write out the .nwk or .tre format. An tutorial can be found Phylogenetic Tree tutorial

Hope this helps.