How to engage with Influencers? - [for Business Development]:
First of all, it all depends on the type of influencer you're trying to reach out to, as well as what you're trying to accomplish based on your business goals. To engage with influencers, building relationships and trust should be the foundation of your sincere approach because they make your efforts for business development easier.
“Instagram is still the major creator channel with $2.23 billion spent on influencer marketing just in the U.S. this year – mostly thanks to the “wide range of shoppable content” – eMarketer’s Influencer Marketing Report 
One strategy is to research potential influencers and find out who they're connected to and who they follow on social media. You can then try reaching out to these individuals and asking for an introduction. Try to develop a relationship with them.
Another option is to send an email or direct message on social media introducing yourself and your business and asking for their help. Collaborate with influencers on content that interests you.
Another tip is to be patient and understanding when reaching out to influencers. They are likely very busy and may not respond right away, or they may not be interested in working with you. Be persistent, but don't be pushy or aggressive in your efforts.
Once you do connect with an influencer, it's important to respect their time and be prepared with your pitch. Make sure you know why you're reaching out to them, what you'd like them to do for you, and how exactly they can help your business or project.
Be clear about your goals, what you're offering in return, and how you can contribute to the relationship as well.
Don't forget about follow-up – it's one of the most important steps in building a relationship. Make sure you stay in touch by following up after your pitch, keeping the conversation going, and checking in from time to time to ensure that the relationship is healthy and strong.
Also, meet them face-to-face at events and conferences, connect with them on LinkedIn, and give them exclusive access to your content. It's also important to stay in regular contact with influencers so that you can stay updated on the interests and needs of their audiences.
This will also help keep the relationship strong and maintain a two-way communication channel.
“Influencer ROI is also 11 times greater than other digital marketing tactics, generating $5.20 for every dollar spent” - Retail Dive and afluencer
Overall, if you want to recruit influencers for your brand, you need to show them that you have a vision for the future and are committed to making positive changes in the world.
Be transparent about your company's goals and try to build a relationship and trust to make your business development efforts easier than ever.
P.S: Visit Digital Marketing Forum that answers [most un-answered] questions.
P.S.S: Please don’t forget to forward this blog post to your network so they can get the best tips, practices, strategies, education, resources, and tools to help their businesses grow.