doing some ontology enrichment analysis

Question

I have my RNA sequencing results output from DeSEQ2 and eager to generate some figures. I try to run the following command, only for it to tell me that the input does not match the required format, when I clearly see that it is not true. Please if anybody knows how to fix this bug, I would kindly appreciate your contribution in comment section further.

GO.params.bp <- GSEAGOHyperGParams(name="GOstats", 
                                    geneSetCollection=gene_annotations, 
                                    geneIds = ensembl_gene_ids, 
                                    universeGeneIds = NULL,  
                                    ontology = "BP", 
                                    pvalueCutoff = cutoff,  
                                    conditional = FALSE, 
                                    testDirection = "over")

Error in (function (classes, fdef, mtable) : unable to find an inherited method for function ‘geneIdType’ for signature ‘"character"’

str(ensembl_gene_ids)

chr [1:3] "ENSG00000100592" "ENSG00000101336" "ENSG00000134285"

class(ensembl_gene_ids) 

[1] "character"