Though you have not yet enter either /organism or /mol_type on annotation table, you click [Confirm] button.
You must fill mandatory items of annotation (feature, location, qualifier) before clicking [Confirm] button.

On 7.Annotation, click [Select Qualifier] button beside ‘source’, and select qualifiers as needed. Then, click [Edit] button beside entry name and input /organism and others. Note that it is required to input at least one feature other than source.
See also 7.Annotation – Organism name.