Only Cancel button in LookupMode

Dynamics 365 Business Central/NAV Developers Forum
1

I have a page as a CardPart type. And I want to select multiple values from the custom list page. But when I run RunModal with LookupOk no OK button shows up, only Cancel.

field(SelectedCompanies; Rec.SelectedCompanies)
            {
                Editable = true;
                Caption = 'Selected Companies';
                ToolTip = 'Select companies you want to use';
                ApplicationArea = All;
                trigger OnLookup(var Text: Text): Boolean
                var
                    recdref: RecordRef;
                    companyPage: Page BI4SelectCompaniesPage;
                    RecCodeunit: Codeunit SelectionFilterManagement;
                    recCompany: Record Company;
                begin
                    Clear(companyPage);
                    Clear(recCompany);
                    recdref.GetTable(recCompany);
                    companyPage.LookupMode := true;
                    if companyPage.RunModal() = Action::LookupOK then begin
                        companyPage.SetSelectionFilter(recCompany);
                        Text += RecCodeunit.GetSelectionFilter(recdref, recCompany.FieldNo(Name));
                    end else
                        exit(false);
                end;
            }