documentclass[12pt, fleqn]{scrreprt}

usepackage[utf8]{inputenc}
usepackage[english,main=ngerman]{babel}
usepackage[ backend=biber, indexing=cite, citestyle=authoryear, bibstyle=authoryear, isbn=false, firstinits=true, language=ngerman, natbib=true, maxbibnames=99, maxcitenames=3
    %url=false
]{biblatex}
bibliography{example}

DefineBibliographyStrings{ngerman}{%
  andothers ={etaddabbrvspace aladddot},
  andmore ={etaddabbrvspace aladddot},
}

renewcommand*{labelnamepunct}{addcolonspace}
DeclareFieldFormat{journaltitle}{{#1}}
DeclareFieldFormat{issuetitle}{{#1}}
DeclareFieldFormat{maintitle}{{#1}}
DeclareFieldFormat{booktitle}{{#1}}
DeclareFieldFormat
  [article,inbook,incollection,inproceedings,patent,thesis,unpublished]
  {title}{{#1isdot}}
usepackage{xpatch}
xpretobibmacro{author}{begingroupitshape}{}{}
xapptobibmacro{author}{endgroup}{}

begin{document}

2 Authors:

Parentcite: parencite{gencc.2015}

Textcite: textcite{gencc.2015}


3 Authors:

Parentcite: parencite{hsu.2013}

Textcite: textcite{hsu.2013}

Multiple Authors:

Parentcite: parencite{gibbs.2015}

Textcite: textcite{gibbs.2015}

newpage
addcontentsline{toc}{chapter}{Literaturverzeichnis}
printbibliography[title=Literaturverzeichnis]

end{document}

@article{gencc.2015,
  title={A fact or an illusion: Effective social media usage of female entrepreneurs},
  author={Gen{c{c}}, Merve and {"O}ks{"u}z, Burcu},
  journal={Procedia-Social and Behavioral sSciences},
  volume={195},
  pages={293--300},
  year={2015},
  publisher={Elsevier}
}

@article{hsu.2013,
  title={The effects of blogger recommendations on customers’ online shopping intentions},
  author={Hsu, A and Chuan, Judy and Moll, Hsiu-Sen},
  journal={Internet Research},
  volume={23},
  number={1},
  pages={69--88},
  year={2013},
  publisher={Emerald Group Publishing Limited}
}

@article{gibbs.2015,
  title={# Funeral and Instagram: death, social media, and platform vernacular},
  author={Gibbs, Martin and Meese, James and Arnold, Michael and Nansen, Bjorn and Carter, Marcus},
  journal={Information, Communication & Society},
  volume={18},
  number={3},
  pages={255--268},
  year={2015},
  publisher={Taylor & Francis}
}