Hi there,

Have you tried checking the below documentation where there is an explanation to save as pdf functionality to vfpage:

> https://developer.salesforce.com/docs/atlas.en-us.pages.meta/pages/pages_output_pdf_print_as_pdf_button.htm

I hope this helps and in case if this comes handy can you please choose this as best answer so that it can be used by others in the future.

Below is the code referd in above documentation
 

public class SaveAsPdfExtension {

    // Required extension constructor (empty, no-op)
    public SaveAsPDFExtension(ApexPages.StandardController controller) {}
    
    // Determines what kind of rendering to use for the page request
    public String renderingService { get; private set; }
    
    // Allow the page to set the PDF file name
    public String renderedFileName { 
        get; 
        set { renderedFileName = this.sanitizeFileName(value); }
    }

    // Rendered content MIME type, used to affect HTTP response
    public String renderedContentType {
        get {
            String renderedContentType = 'text/html'; // the default
            
            if( ! this.renderingAsHtml() ) {
                // Provides a MIME type for a PDF document 
                renderedContentType = 'application/pdf';
                
                // Add a file name for the PDF file
                if( this.renderedFileName != null) {
                    // This is supposed to set the file name, but it doesn't work
                    renderedContentType += '#' + this.renderedFileName;
                    
                    // This is a work-around to set the file name
                    ApexPages.currentPage().getHeaders().put(
                        'content-disposition', 'attachment; filename=' + 
                         this.renderedFileName);
                }
            }
            
            return renderedContentType;
        }
    }
    
    // Are we rendering to HTML or PDF?
    public Boolean renderingAsHtml() {
        return ( (renderingService == null) || 
                 ( ! renderingService.startsWith('PDF')) );
    }

    // Action method to save (or "print") to PDF
    public PageReference saveToPdf() {
        renderingService = 'PDF';
        return null;
    }
    
    // Private helper -- basic, conservative santization
    private String sanitizeFileName(String unsafeName) {
        String allowedCharacters = '0-9a-zA-Z-_.';
        String sanitizedName = 
            unsafeName.replaceAll('[^' + allowedCharacters + ']', '');
        // You might also want to check filename length, 
        // that the filename ends in '.pdf', etc.
        return(sanitizedName);
    }
}