No, with
@KarenRei's spreads the written higher price call is protected by the lower price lower leg call, so they are self-covered (no need for shares or cash backing), and capital requirements are basically the worst-case loss times the number of calls.
So for example, if you buy a $1,000 strike 2021/01/15 for $110 and sell a $1,200 strike (same expiry) for $75 to create a leveraged bullish spread, then the worst-case loss is the difference between the two premiums: $65 × 100 = $6,500 if TSLA closes below $1,200 on 2021/01/15.
With $160k of capital you can buy 24 such contracts.
With narrower spreads - for example a $1,100 upper leg for $90 your worst-case loss is $20, and your $160k cash will finance up to 80 such spreads, without using margin.
Note that if you start trading call spreads it's highly recommended you look up buy limit and sell limit orders and post your buy and sell orders at around the mid-price, the bid-ask price-spreads are rather substantial for the 2021 expiries that Karen is using, and will eat up a lot of the gains if you just buy/sell naively.
It's also recommended to put your limit orders in well in advance and wait for the market come to you, with occasional adjustments as new events come in and the price develops, i.e. do not try to react to price spikes (there's exceptions though) - you are just not fast enough for that and it's also stressful and emotional.
Another warning: on most retail trading platforms it's dreadfully easy to accidentally write naked puts or naked calls. You might want to ask your broker whether that can be enforced, i.e. let your account be downgraded to not allow naked options at all - only covered options and spreads. Not having margin enabled (i.e. a cash-only options trading account) is a solution.
If not then try to find some procedure that keeps you safe, for example by always double checking the balance of your spreads - and also be careful about always starting with the lower leg: if you write the upper leg first you will for a short amount of time own a naked call. If some huge event comes in or should you lose Internet connectivity at just the wrong moment and the price crashes, your losses with a naked call are almost unlimited. I.e. think through the consequences and try to be worst-case transaction-safe in multi-options strategies.
Same applies to closing and rolling a spread:
always have at least as many long calls as short calls. No exceptions allowed: if you are trading in a personal retail account then your brokerage agreement makes you liable for any trading losses without limits, including all your personal and joint wealth, including your car, your home, all other bank accounts and more. Brokerages routinely go after retail clients that blew out with huge negative account balances, if the client doesn't pay they will sue and win, and if the client still doesn't pay the debt is sold to a debt collection agency.
Many platforms will allow you to safely enter into and exit from spreads, but rolling them as
@KarenRei does is usually manual work.
Not advice and double check my calculations!