In file: https://bitbucket.org/atlassian/atlassian-connect-express/src/master/types/index.d.ts
The interface StoreAdapter is wrong.
interface StoreAdapter {
del(key: string, clientKey: string): Promise<void>;
get(key: string, clientKey: string): Promise<any>;
set(key: string, clientKey: string): Promise<any>; // Wrong it should be: set(key: string, value: any, clientKey: string): Promise<any>;
}